code: public static Type[] getParameterTypes(Type generic) {
  		Type[] types = null;
  		if(isGeneric(generic)) {
  			types = ((ParameterizedType)generic).getActualTypeArguments();
  		}
  		return types;
  	}
docs: Returns the parameter types for a generic container, e.g. it would return
  <code>{String, int}</code> for a <code>Map&lt;String, int&gt;</code>.
  
  @param generic
  the generic class.
  @return
  the parameter types of a generic container, null otherwise.