code: @Override
  	public CallableStatement prepareCall(String sql) throws SQLException {
  		return new SimonCallableStatement(conn, conn.prepareCall(sql), sql, prefix);
  	}
docs: Calls real prepareCall and wraps returned statement by Simon's statement.
  
  @param sql an SQL statement, typically a JDBC function call escape string
  @return Simon's statement with wrapped real statement
  @throws java.sql.SQLException if real operation fails