When final injunction granted

Except when 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. When pecuniary compensation would not afford adequate relief; 2. When it would be extremely difficult to ascertain the amount of compensation which would afford adequate relief; 3. When the restraint is necessary to prevent a multiplicity of judicial proceedings; or 4. When the obligation arises from a trust.