code: public static String parseExplainCall(String statement)
      {
          Matcher matcher = ExplainCallPreamble.matcher(statement);
          if ( ! matcher.lookingAt()) {
              return null;
          }
          return statement.substring(matcher.end());
      }
docs: Parse EXPLAIN <query>
  @param statement  statement to parse
  @return           query parameter string or NULL if statement wasn't recognized