Small fixes for #758 (#1057)

Signed-off-by: Bogdan Drutu <bogdandrutu@gmail.com>

api/src/main/java/io/opentelemetry/trace/attributes/BooleanAttributeSetter.java

@@ -36,7 +36,6 @@ public final class BooleanAttributeSetter {
   private final String attributeKey;
 
   private BooleanAttributeSetter(String attributeKey) {
-    super();
     if (attributeKey == null || attributeKey.length() == 0) {
       throw new IllegalArgumentException("attributeKey cannot be empty");
     }

api/src/main/java/io/opentelemetry/trace/attributes/DoubleAttributeSetter.java

@@ -36,7 +36,6 @@ public final class DoubleAttributeSetter {
   private final String attributeKey;
 
   private DoubleAttributeSetter(String attributeKey) {
-    super();
     if (attributeKey == null || attributeKey.length() == 0) {
       throw new IllegalArgumentException("attributeKey cannot be empty");
     }

api/src/main/java/io/opentelemetry/trace/attributes/LongAttributeSetter.java

@@ -36,7 +36,6 @@ public final class LongAttributeSetter {
   private final String attributeKey;
 
   private LongAttributeSetter(String attributeKey) {
-    super();
     if (attributeKey == null || attributeKey.length() == 0) {
       throw new IllegalArgumentException("attributeKey cannot be empty");
     }

api/src/main/java/io/opentelemetry/trace/attributes/StringAttributeSetter.java

@@ -37,7 +37,6 @@ public final class StringAttributeSetter {
   private final String attributeKey;
 
   private StringAttributeSetter(String attributeKey) {
-    super();
     if (attributeKey == null || attributeKey.length() == 0) {
       throw new IllegalArgumentException("attributeKey cannot be empty");
     }

api/src/test/java/io/opentelemetry/trace/attributes/SemanticAttributesTest.java

@@ -45,8 +45,8 @@ public class SemanticAttributesTest {
   public void shouldEnableSetAttributeOnSpan() throws IllegalAccessException {
     Set<String> keys = new HashSet<>();
     Field[] fields = SemanticAttributes.class.getFields();
-    for (int i = 0; i < fields.length; i++) {
-      Object attribute = fields[i].get(null);
+    for (Field field : fields) {
+      Object attribute = field.get(null);
       if (attribute instanceof StringAttributeSetter) {
         keys.add(((StringAttributeSetter) attribute).key());
         ((StringAttributeSetter) attribute).set(span, "TestValue");