code: protected boolean isGetterMethod(ExecutableElement executableElement) {
  
          // must have a return value
          TypeMirror returnTypeMirror = executableElement.getReturnType();
  
          if (returnTypeMirror.getKind().equals(TypeKind.VOID)) {
              error(executableElement, "method %s must have a non void return type", executableElement.getSimpleName().toString());
              return false;
          }
  
          // check if method takes no parameters
          List parameters = executableElement.getParameters();
          if (parameters != null && parameters.size() > 0) {
              error(executableElement, "method %s must have no parameters ", executableElement.getSimpleName().toString());
              return false;
          }
  
          return true;
      }
docs: Checks if passed element has a non void return type and takes no parameters
  
  @param executableElement
  @return true if passed element has a non void return type and takes no parameters