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: difflib.go
    path of file: ./repos/zeebe/clients/go/vendor/github.com/pmezard/go-difflib/difflib
    
    the code of the file until where you have to start completion: // Package difflib is a partial port of Python di
    
func (m *SequenceMatcher) QuickRatio() float64 {
	// viewing a and b as multisets, set matches to the cardinality
	// of their intersection; this counts the number of matches
	// without regard to order, so is clearly an upper bound
	if m.fullBCount == nil {
		m.fullBCount = map[string]int{}
		for _, s := range m.b {
			m.fullBCount[s] = m.fullBCount[s] + 1
		}
	}

	// avail[x] is the number of times x appears in 'b' less the
	// number of times we've seen it in 'a' so far ... kinda
	avail := map[string]int{}
	matches := 0
	for _, s := range m.a {
		n, ok := avail[s]
		if !ok {
			n = m.fullBCount[s]
		}
		avail[s] = n - 1
		if n > 0 {
			matches += 1
		}
	}
	return calculateRatio(matches, len(m.a)+len(m.b))
}