You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: processtree.go
    path of file: ./repos/tracee/pkg/filters
    
    the code of the file until where you have to start completion: package filters

import (
	"strconv"
	"strings"

	"golang.org/x/exp/maps"

	"github.com/aquasecurity/tracee/pkg/errfmt"
	"github.com/aquasecurity/tracee/pkg/utils"
)

type ProcessTreeFilter struct {
	equal    map[uint32]struct{} // k=pid states that pid and its descendent should be traced
	notEqual
    
func (f *ProcessTreeFilter) Parse(operatorAndValues string) error {
	if len(operatorAndValues) < 2 {
		return InvalidExpression(operatorAndValues)
	}

	var (
		equalityOperator bool
		valuesString     string
	)

	if strings.HasPrefix(operatorAndValues, "=") {
		valuesString = operatorAndValues[1:]
		equalityOperator = true
	} else if strings.HasPrefix(operatorAndValues, "!=") {
		valuesString = operatorAndValues[2:]
		if len(valuesString) == 0 {
			return errfmt.Errorf("no value passed with operator in process tree filter")
		}
		equalityOperator = false
	} else {
		return InvalidExpression(operatorAndValues)
	}

	values := strings.Split(valuesString, ",")
	for _, value := range values {
		pid, err := strconv.ParseUint(value, 10, 32)
		if err != nil {
			return errfmt.Errorf("invalid PID given to filter: %s", valuesString)
		}
		if equalityOperator {
			f.equal[uint32(pid)] = struct{}{}
		} else {
			f.notEqual[uint32(pid)] = struct{}{}
		}
	}

	f.Enable()

	return nil
}