code: public Map<String, Object> jsonToMap(String json) {
  
          /*
           * This if block treats the /v2/accounts/exists response. Currently the endpoint returns the status
           * code on its response body, breaking the JSON conversion.
           */
          if ("200".equals(json)) {
              this.responseBody.put("code", 200);
              return this.responseBody;
          }
  
          if ("400".equals(json)) {
              this.responseBody.put("code", 400);
              return this.responseBody;
          }
  
          if ("404".equals(json)) {
              this.responseBody.put("code", 404);
              return this.responseBody;
          }
  
          if (!json.equals("")) {
              ObjectMapper mapper = new ObjectMapper();
              try {
                  this.responseBody = mapper.readValue(json, new TypeReference<Map<String, Object>>(){});
              } catch (IOException e) {
                  e.printStackTrace();
              }
          }
          return this.responseBody;
      }
docs: This method is used to receive the JSON returned from API and cast it to a Map.
  
  @param   json
  {@code String} the JSON returned from API, by {@code InputStream}.
  
  @return  {@code Map}