diff --git a/pom.xml b/pom.xml
index 4f0b4449..849f03d0 100644
--- a/pom.xml
+++ b/pom.xml
@@ -2,7 +2,7 @@
     <modelVersion>4.0.0</modelVersion>
     <groupId>com.testdroid</groupId>
     <artifactId>testdroid-api</artifactId>
-    <version>3.13</version>
+    <version>3.14</version>
     <packaging>jar</packaging>
     <name>Bitbar API v2</name>
     <url>https://github.com/bitbar/testdroid-api</url>
diff --git a/src/main/java/com/testdroid/api/APIList.java b/src/main/java/com/testdroid/api/APIList.java
index fdc071b3..67f9c9a9 100644
--- a/src/main/java/com/testdroid/api/APIList.java
+++ b/src/main/java/com/testdroid/api/APIList.java
@@ -47,23 +47,19 @@ public APIList() {
     }
 
     public APIList(String requestURL, List<T> data, Integer total, Context<T> ctx) {
-        int offset = ctx.getOffset();
-        int limit = ctx.getLimit();
-        String search = ctx.getSearch();
-        String sort = ctx.getSort().serialize();
         this.total = total;
-        this.offset = offset;
-        this.limit = limit;
-        this.search = search;
-        this.sort = sort;
+        this.offset = ctx.getOffset();
+        this.limit = ctx.getLimit();
+        this.search = ctx.getSearch();
+        this.sort = ctx.getSort().serialize();
         this.data = data;
         this.context = ctx;
         String filter = filterParam(ctx.getFilters());
         if (offset + limit < total) {
-            this.next = getListURL(requestURL, offset + limit, limit, search, sort, filter);
+            this.next = getListURL(requestURL, offset.longValue() + limit, limit, search, sort, filter);
         }
         if (offset - limit >= 0) {
-            this.previous = getListURL(requestURL, offset - limit, limit, search, sort, filter);
+            this.previous = getListURL(requestURL, offset.longValue() - limit, limit, search, sort, filter);
         }
     }
 
diff --git a/src/main/java/com/testdroid/api/AbstractAPIClient.java b/src/main/java/com/testdroid/api/AbstractAPIClient.java
index 2eb8ac48..ded83ba9 100644
--- a/src/main/java/com/testdroid/api/AbstractAPIClient.java
+++ b/src/main/java/com/testdroid/api/AbstractAPIClient.java
@@ -231,8 +231,7 @@ protected <T extends APIEntity> T postOnce(
         } catch (HttpResponseException ex) {
             throw getAPIException(ex);
         } catch (IOException ex) {
-            throw new APIException(String
-                    .format("Failed to execute API call: %s. Reason: %s", uri, ex.getMessage()), ex);
+            throw new APIException(String.format(FAILED_TO_EXECUTE_API_CALL_WITH_REASON, uri, ex.getMessage()), ex);
         } finally {
             disconnectQuietly(response);
         }
@@ -272,8 +271,7 @@ protected void deleteOnce(String uri) throws APIException {
         } catch (HttpResponseException ex) {
             throw getAPIException(ex);
         } catch (IOException ex) {
-            throw new APIException(String
-                    .format("Failed to execute API call: %s. Reason: %s", uri, ex.getMessage()), ex);
+            throw new APIException(String.format(FAILED_TO_EXECUTE_API_CALL_WITH_REASON, uri, ex.getMessage()), ex);
         } finally {
             disconnectQuietly(response);
         }
diff --git a/src/main/java/com/testdroid/api/DefaultAPIClient.java b/src/main/java/com/testdroid/api/DefaultAPIClient.java
index 8bbaf39c..28c66fa1 100644
--- a/src/main/java/com/testdroid/api/DefaultAPIClient.java
+++ b/src/main/java/com/testdroid/api/DefaultAPIClient.java
@@ -41,7 +41,7 @@
  */
 public class DefaultAPIClient extends AbstractAPIClient {
 
-    private static final Logger LOGGER = LoggerFactory.getLogger(APIKeyClient.class);
+    private static final Logger LOGGER = LoggerFactory.getLogger(DefaultAPIClient.class);
 
     public static final int HTTP_CONNECT_TIMEOUT = 60000;
 
diff --git a/src/main/java/com/testdroid/api/dto/Type.java b/src/main/java/com/testdroid/api/dto/Type.java
deleted file mode 100644
index 885e34ab..00000000
--- a/src/main/java/com/testdroid/api/dto/Type.java
+++ /dev/null
@@ -1,27 +0,0 @@
-package com.testdroid.api.dto;
-
-/**
- * Enum represents type of argument to parsing
- * <ul>
- * <li><code>N</code> stands for <code>Number</code> type
- * <li><code>D</code> stands for <code>Date</code> type
- * <li><code>S</code> stands for <code>String</code> type
- * <li><code>B</code> stands for <code>Boolean</code> type
- * <li><code>LN<code/> stands for <code>List<Number></code> type
- * <li><code>LD<code/> stands for <code>List<Date></code> type
- * <li><code>LS<code/> stands for <code>List<String></code> type
- * <li><code>LB<code/> stands for <code>List<Boolean></code> type
- * </ul>
- *
- * @author Damian Sniezek <damian.sniezek@bitbar.com>
- */
-public enum Type {
-    N,
-    D,
-    S,
-    B,
-    LN,
-    LD,
-    LS,
-    LB
-}
diff --git a/src/main/java/com/testdroid/api/model/APIAccountService.java b/src/main/java/com/testdroid/api/model/APIAccountService.java
index 80531c3a..8ba170cc 100644
--- a/src/main/java/com/testdroid/api/model/APIAccountService.java
+++ b/src/main/java/com/testdroid/api/model/APIAccountService.java
@@ -335,7 +335,7 @@ public Integer getPayUnitCount() {
 
     @JsonIgnore
     public String getVatPriceString() {
-        float vatPrice = (getPrice() * getVatRate()) / 100;
+        float vatPrice = (getPrice() * getVatRate()) / 100f;
         return String.format(Locale.ENGLISH, "%.2f", vatPrice / 100);
     }
 
@@ -346,7 +346,7 @@ public String getNetPriceString() {
 
     @JsonIgnore
     public String getTotalPriceString() {
-        float totalPrice = (getPrice() * (100 + getVatRate())) / 100;
+        float totalPrice = (getPrice() * (100 + getVatRate())) / 100f;
         return String.format(Locale.ENGLISH, "%.2f", totalPrice / 100);
     }
 
diff --git a/src/main/java/com/testdroid/cloud/test/categories/TestTags.java b/src/main/java/com/testdroid/cloud/test/categories/TestTags.java
index 86d9e997..eba5fa8f 100644
--- a/src/main/java/com/testdroid/cloud/test/categories/TestTags.java
+++ b/src/main/java/com/testdroid/cloud/test/categories/TestTags.java
@@ -3,15 +3,19 @@
 /**
  * @author Krzysztof Fonał <krzysztof.fonal@bitbar.com>
  */
-public interface TestTags {
+public class TestTags {
 
-    String UNIT = "unit";
+    private TestTags() {
+        throw new IllegalStateException("Utility class");
+    }
 
-    String API = "api";
+    public static final String UNIT = "unit";
 
-    String INTEGRATION = "integration";
+    public static final String API = "api";
 
-    String API_CLIENT = "api_client";
+    public static final String INTEGRATION = "integration";
 
-    String PORT_FORWARDER_CLIENT = "port_forwarder_client";
+    public static final String API_CLIENT = "api_client";
+
+    public static final String PORT_FORWARDER_CLIENT = "port_forwarder_client";
 }
diff --git a/src/test/java/com/testdroid/api/APIClientTest.java b/src/test/java/com/testdroid/api/APIClientTest.java
index 6878918f..5baaedfa 100644
--- a/src/test/java/com/testdroid/api/APIClientTest.java
+++ b/src/test/java/com/testdroid/api/APIClientTest.java
@@ -22,8 +22,9 @@ class APIClientTest extends BaseAPIClientTest {
     @ArgumentsSource(APIClientProvider.class)
     void td12086(APIClient apiClient) throws APIException {
         APIUser user = apiClient.me();
-        Exception exception = assertThrows(APIException.class, () ->
-                user.getResource(user.selfURI + "/notifications/channels/SLACK+/scopes", APIEnum.class).getEntity());
+        APIResource<APIEnum> resource = user.getResource(user.selfURI + "/notifications/channels/SLACK+/scopes",
+                APIEnum.class);
+        Exception exception = assertThrows(APIException.class, resource::getEntity);
         assertThat(exception.getMessage()).isEqualTo("Invalid Notification Channel: SLACK+");
     }
 
diff --git a/src/test/java/com/testdroid/api/APIDeviceGroupClientTest.java b/src/test/java/com/testdroid/api/APIDeviceGroupClientTest.java
index 2052fe4d..04609057 100644
--- a/src/test/java/com/testdroid/api/APIDeviceGroupClientTest.java
+++ b/src/test/java/com/testdroid/api/APIDeviceGroupClientTest.java
@@ -50,12 +50,13 @@ void addDeviceTest(APIClient apiClient) throws APIException {
     void addSelectorTest(APIClient apiClient) throws APIException {
         APIList<APILabelGroup> labelGroups = apiClient.getLabelGroups(new Context<>(APILabelGroup.class)
                 .addFilter(new FilterEntry(DISPLAY_NAME, EQ, "Device groups"))).getEntity();
-        APILabelGroup deviceGroupLabelGroup = labelGroups.getData().stream().findFirst().get();
+        APILabelGroup deviceGroupLabelGroup = labelGroups.getData().stream().findFirst().orElseThrow(APIException::new);
         APIList<APIDeviceProperty> apiDeviceProperties = deviceGroupLabelGroup.getDevicePropertiesResource(new
                 Context<>(APIDeviceProperty.class)
                 .addFilter(new FilterEntry(DISPLAY_NAME, EQ, "Android devices")))
                 .getEntity();
-        APIDeviceProperty androidDevicesLabel = apiDeviceProperties.getData().stream().findFirst().get();
+        APIDeviceProperty androidDevicesLabel = apiDeviceProperties.getData().stream().findFirst()
+                .orElseThrow(APIException::new);
         APIDeviceGroup dynamicAndroidDeviceGroup = apiClient.me()
                 .createDeviceGroup("dynamicAndroidDeviceGroup", ANDROID);
         dynamicAndroidDeviceGroup = dynamicAndroidDeviceGroup.addSelector(androidDevicesLabel);
diff --git a/src/test/java/com/testdroid/api/APIProjectAPIClientTest.java b/src/test/java/com/testdroid/api/APIProjectAPIClientTest.java
index 068186ff..25614600 100644
--- a/src/test/java/com/testdroid/api/APIProjectAPIClientTest.java
+++ b/src/test/java/com/testdroid/api/APIProjectAPIClientTest.java
@@ -1,6 +1,7 @@
 package com.testdroid.api;
 
 import com.testdroid.api.model.APIProject;
+import com.testdroid.api.model.APIUser;
 import org.junit.jupiter.api.Tag;
 import org.junit.jupiter.params.ParameterizedTest;
 import org.junit.jupiter.params.provider.ArgumentsSource;
@@ -38,11 +39,10 @@ void updateProjectTest(APIClient apiClient) throws APIException {
     @ParameterizedTest
     @ArgumentsSource(BaseAPIClientTest.APIClientProvider.class)
     void deleteProjectTest(APIClient apiClient) throws APIException {
-        APIProject project = apiClient.me().createProject(generateUnique("testProject"));
+        APIUser me = apiClient.me();
+        APIProject project = me.createProject(generateUnique("testProject"));
         project.delete();
-        assertThatThrownBy(() ->
-                apiClient.me().getProject(project.getId()))
-                .isInstanceOf(APIException.class)
+        assertThatThrownBy(() -> me.getProject(project.getId())).isInstanceOf(APIException.class)
                 .hasMessageContaining(String.format("Project with id %d does not exist", project.getId()));
     }
 }
diff --git a/src/test/java/com/testdroid/api/BaseAPIClientTest.java b/src/test/java/com/testdroid/api/BaseAPIClientTest.java
index ac6591d6..1a87da27 100644
--- a/src/test/java/com/testdroid/api/BaseAPIClientTest.java
+++ b/src/test/java/com/testdroid/api/BaseAPIClientTest.java
@@ -101,7 +101,7 @@ APIFramework getApiFramework(APIClient apiClient, String frameworkNameLike) thro
 
     protected static APIUser create(APIKeyClient adminApiClient) throws APIException {
         Map<String, Object> map = new HashMap<>();
-        map.put(EMAIL, generateUniqueEmail(EMAIL_PATTERN));
+        map.put(EMAIL, generateUniqueEmail());
         APIUser userForTest = adminApiClient.post("/admin/users", map, APIUser.class);
         map.clear();
         map.put(EMAIL, userForTest.getEmail());
@@ -111,8 +111,8 @@ protected static APIUser create(APIKeyClient adminApiClient) throws APIException
         return userForTest;
     }
 
-    private static String generateUniqueEmail(String emailPattern) {
-        return String.format(emailPattern, System.currentTimeMillis());
+    private static String generateUniqueEmail() {
+        return String.format(EMAIL_PATTERN, System.currentTimeMillis());
     }
 
     static String generateUnique(String prefix) {
@@ -126,6 +126,7 @@ static DefaultAPIClient createDefaultApiClientWithProxy(HttpHost proxy) throws A
     }
 
     static File loadFile(String name) {
-        return new File(BaseAPIClientTest.class.getResource(name).getFile());
+        java.net.URL url = BaseAPIClientTest.class.getResource(name);
+        return new File(Objects.requireNonNull(url).getFile());
     }
 }