code: public <X, PP extends MessagePathParameter<X>> X getPathParameter(Class<PP> parameterClass) {
  		@SuppressWarnings("unchecked")
  		PP pathParameter = (PP) pathParameters.get(parameterClass);
  		Preconditions.checkState(pathParameter != null, "No parameter could be found for the given class.");
  		return pathParameter.getValue();
  	}
docs: Returns the value of the {@link MessagePathParameter} for the given class.
  
  @param parameterClass class of the parameter
  @param <X>            the value type that the parameter contains
  @param <PP>           type of the path parameter
  @return path parameter value for the given class
  @throws IllegalStateException if no value is defined for the given parameter class