code: public <T> Map<String, T> unmarshalMap(Class<T> returnType, Reader reader) throws JsonParseException, JsonMappingException, IOException {
          ObjectMapper objectMapper = getContext(null);
          return (objectMapper.readValue(reader, new TypeReference<Map<String, T>>() {}));
      }
docs: Unmarshal the JSON data on the specified Reader instance and populate a Map of String keys and values of the provided returnType class.
  
  @param <T> the generics type for the Map value
  @param returnType an instance of this type class will be contained the values of the Map
  @param reader the Reader instance that contains the JSON data
  @return a Map containing the parsed data from the Reader
  @throws JsonParseException when an error occurs parsing the provided JSON
  @throws JsonMappingException if a JSON error occurs
  @throws IOException if an error occurs reading the JSON data