build/change_trust.go
func (m Limit) MutateChangeTrust(o *xdr.ChangeTrustOp) (err error) {
	o.Limit, err = amount.Parse(string(m))
	return
}
func (m Limit) MutateChangeTrust(o *xdr.ChangeTrustOp) (err error) {
	o.Limit, err = amount.Parse(string(m))
	return
}
// MutateChangeTrust for Limit sets the ChangeTrustOp's Limit field