Under what circumstances perpetual injunction can be granted under the Specific Relief Act, 1963?

According to Section 38 of the Specific Relief Act, 1963 a perpetual injunction may be granted to the plaintiff to prevent the breach of an obligation existing in his favour, whether expressly or by implication. When any such obligation arises from contract, the court shall be guided by the rules and provisions contained in Chapter II. When the defendant invades or threatens to invade the plaintiff's right to, or enjoyment of, property, the court may grant a perpetual injunction in the following cases, namely:- where the defendant is trustee of the property for the plaintiff; where there exists no standard for ascertaining the actual damage caused, or likely to be caused, by the invasion; where the invasion is such that compensation in money would not afford adequate relief; where the injunction is necessary to prevent a multiplicity of judicial proceedings.