code: public static function singleDocument($document)
      {
          if (gettype($document)!="array" && gettype($document)!="object") {
              throw new ClusterpointException("\"->insert()\" function: parametr passed ".json_encode(self::escape_string($document))." is not in valid document format.", 9002);
          }
          $query = "{";
          $first = true;
          foreach ($document as $key => $value) {
              if (!$first) {
                  $query .= ",";
              }
              $query .= '"'.self::escape_string($key).'" : '.json_encode($value);
              $first = false;
          }
          $query .= '}';
          return $query;
      }
docs: Encode single document in valid format.
  
  @param  mixed $document
  @return string