public static Class<?> wrapperFor(Type primitiveType){
  return requireNonNull(WRAPPERS.get(primitiveType.getTypeName()),"No wrapper found for type '" + primitiveType.getTypeName() + "'.");
}

public static Class < ? > wrapperFor ( Type primitiveType ) { return requireNonNull ( WRAPPERS . get ( primitiveType . getTypeName ( ) ) , "No wrapper found for type '" + primitiveType . getTypeName ( ) + "'." ) ; }
returns the corresponding wrapper type for the specified primitive type . if the type is not primitive , an exception is thrown .
