code: func (tx *Tx) NamedStmtContext(ctx context.Context, stmt *NamedStmt) *NamedStmt {
  	return &NamedStmt{
  		QueryString: stmt.QueryString,
  		Params:      stmt.Params,
  		Stmt:        tx.StmtxContext(ctx, stmt.Stmt),
  	}
  }
docs: // NamedStmtContext returns a version of the prepared statement which runs
  // within a transaction.