public boolean isAssignable(@Nullable Object value){
  if (value == null) {
    return isNullValueAllowed();
  }
  return clazz.isInstance(value);
}

public boolean isAssignable ( @ Nullable Object value ) { if ( value == null ) { return isNullValueAllowed ( ) ; } return clazz . isInstance ( value ) ; }
returns true if the specified value is assignable with this key .
