Except where otherwise provided by this Chapter, a final injunction may be granted to prevent the breach of an obligation existing in favor of the applicant: (1) Where pecuniary compensation would not afford adequate relief; (2) Where it would be extremely difficult to ascertain the amount of compensation which would afford adequate relief; (3) Where the restraint is necessary to prevent a multiplicity of judicial proceedings; or, (4) Where the obligation arises from a trust. SOURCE: CC § 3422.