code: protected final JSerializerType getKeySerializerFromType( JType type ) throws UnsupportedTypeException, UnableToCompleteException {
          return getKeySerializerFromType( type, false, false );
      }
docs: Build the {@link JSerializerType} that instantiate a {@link KeySerializer} for the given type.
  
  @param type type
  @return the {@link JSerializerType}.
  @throws com.github.nmorel.gwtjackson.rebind.exception.UnsupportedTypeException if any.