minor: resolved eclipse saying method could be static

Author: rnveach

src/main/java/org/sonar/plugins/checkstyle/CheckstylePlugin.java

@@ -67,7 +67,7 @@ public final class CheckstylePlugin implements Plugin {
             + "configuration for more information.";
 
     @SuppressWarnings("rawtypes")
-    public List getExtensions() {
+    public static List getExtensions() {
         return Arrays
                 .asList(PropertyDefinition.builder(CheckstyleConstants.CHECKER_FILTERS_KEY)
                                 .defaultValue(CheckstyleConstants.CHECKER_FILTERS_DEFAULT_VALUE)

src/test/java/org/sonar/plugins/checkstyle/CheckstyleConfigurationTest.java

@@ -124,7 +124,7 @@ public void writeConfigurationToWorkingDir() throws IOException {
     public void getCheckstyleConfiguration() throws Exception {
         fileSystem.setEncoding(StandardCharsets.UTF_8);
         final MapSettings mapSettings = new MapSettings(new PropertyDefinitions(
-                System2.INSTANCE, new CheckstylePlugin().getExtensions()));
+                System2.INSTANCE, CheckstylePlugin.getExtensions()));
         mapSettings.setProperty(CheckstyleConstants.CHECKER_FILTERS_KEY,
                 CheckstyleConstants.CHECKER_FILTERS_DEFAULT_VALUE);
         final org.sonar.api.config.Configuration settings = new ConfigurationBridge(mapSettings);

src/test/java/org/sonar/plugins/checkstyle/CheckstylePluginTest.java

@@ -32,8 +32,7 @@ public class CheckstylePluginTest {
 
     @Test
     public void testGetExtensions() {
-        final CheckstylePlugin plugin = new CheckstylePlugin();
-        assertThat(plugin.getExtensions().size()).isGreaterThan(1);
+        assertThat(CheckstylePlugin.getExtensions().size()).isGreaterThan(1);
     }
 
     @Test

src/test/java/org/sonar/plugins/checkstyle/CheckstyleProfileExporterTest.java

@@ -254,7 +254,7 @@ public void addTabWidthProperty() {
     @SuppressWarnings("unchecked")
     private void initSettings(@Nullable String key, @Nullable String property) {
         final MapSettings mapSettings = new MapSettings(
-                new PropertyDefinitions(System2.INSTANCE, new CheckstylePlugin().getExtensions()));
+                new PropertyDefinitions(System2.INSTANCE, CheckstylePlugin.getExtensions()));
         if (Objects.nonNull(key)) {
             mapSettings.setProperty(key, property);
         }