code: func (sc *StatementContext) AppendWarning(warn error) {
  	sc.mu.Lock()
  	if len(sc.mu.warnings) < math.MaxUint16 {
  		sc.mu.warnings = append(sc.mu.warnings, SQLWarn{WarnLevelWarning, warn})
  	}
  	sc.mu.Unlock()
  }
docs: // AppendWarning appends a warning with level 'Warning'.