code: public Double readDouble() throws IOException {
          String temp = this.readField(false /* isQuotedString */);
  
          if (Utility.isNullOrEmpty(temp)) {
              return null;
          }
          else {
              return Double.parseDouble(temp);
          }
      }
docs: Read a Double from the stream.
  
  @return
  the Double read.
  @throws IOException