code: private MethodSpec buildNewDeserializerMethod( JClassType mappedTypeClass ) throws UnableToCompleteException {
          JDeserializerType type;
          try {
              type = getJsonDeserializerFromType( mappedTypeClass );
          } catch ( UnsupportedTypeException e ) {
              logger.log( Type.ERROR, "Cannot generate mapper due to previous errors : " + e.getMessage() );
              throw new UnableToCompleteException();
          }
  
          return MethodSpec.methodBuilder( "newDeserializer" )
                  .addModifiers( Modifier.PROTECTED )
                  .addAnnotation( Override.class )
                  .returns( parameterizedName( JsonDeserializer.class, mappedTypeClass ) )
                  .addStatement( "return $L", type.getInstance() )
                  .build();
      }
docs: Build the new deserializer method.
  
  @param mappedTypeClass the type to map
  
  @return the method