code: public static Class<?> getMethodReturnType(Class<?> clazz, String methodName, Class<?>... parameterTypes) {
          Method m = getMethod(clazz, methodName, parameterTypes);
  
          if (m == null) {
              return null;
          }
  
          return m.getReturnType();
      }
docs: Returns the return type of a method if it exists within the class.
  Calling this method is equal to calling {@link ReflectionUtils#getMethod(Class, String, Class[])} with
  a null check and finally return the type via getReturnType().
  
  @param clazz          The class within to look for the method with the given method
  name
  @param methodName     The name of the method to be returned
  @param parameterTypes The accepting parameter types of the method
  @return The return type of the method if it can be found, otherwise null
  @see ReflectionUtils#getMethod(Class, String, Class[])