orm.go
func (f *Field) RowsPreviousColumn(rowIDOrKey interface{}, columnIDOrKey interface{}) *PQLRowsQuery {
	rowIDKey, err := formatIDKey(rowIDOrKey)
	if err != nil {
		return NewPQLRowsQuery("", f.index, err)
	}
	columnIDKey, err := formatIDKey(columnIDOrKey)
	if err != nil {
		return NewPQLRowsQuery("", f.index, err)
	}
	text := fmt.Sprintf("Rows(field='%s',previous=%s,column=%s)", f.name, rowIDKey, columnIDKey)
	return NewPQLRowsQuery(text, f.index, nil)
}
func (f *Field) RowsPreviousColumn(rowIDOrKey interface{}, columnIDOrKey interface{}) *PQLRowsQuery {
	rowIDKey, err := formatIDKey(rowIDOrKey)
	if err != nil {
		return NewPQLRowsQuery("", f.index, err)
	}
	columnIDKey, err := formatIDKey(columnIDOrKey)
	if err != nil {
		return NewPQLRowsQuery("", f.index, err)
	}
	text := fmt.Sprintf("Rows(field='%s',previous=%s,column=%s)", f.name, rowIDKey, columnIDKey)
	return NewPQLRowsQuery(text, f.index, nil)
}
// RowsPreviousColumn creates a Rows query with the given previous row ID/key and column ID/key