func (b bracketPairs) Len() int           { return len(b) }
func (b bracketPairs) Swap(i, j int)      { b[i], b[j] = b[j], b[i] }
func (b bracketPairs) Less(i, j int) bool { return b[i].opener < b[j].opener }

// resolvePairedBrackets runs the paired bracket part of the UBA algorithm.
//
// For each rune, it takes the indexes into the original string, the class the
// bracket type (in pairTypes) and the bracket identifier (pairValues). It also

	for _, seq := range p.determineIsolatingRunSequences() {
		// 3) resolving weak types
		// Rules W1-W7.
		seq.resolveWeakTypes()

		// 4a) resolving paired brackets
		// Rule N0
		resolvePairedBrackets(seq)

		// 4b) resolving neutral types
		// Rules N1-N3.
		seq.resolveNeutralTypes()

		// 5) resolving implicit embedding levels
		// Rules I1, I2.
		seq.resolveImplicitLevels()