Except where otherwise provided by the provisions of the code governing specific and preventive relief (chapter 1, part 4, of this title and Title 28, chapter 2, parts 16 and 17), a final injunction may be granted to prevent the breach of an obligation existing in favor of the applicant where:
(1) pecuniary compensation would not afford adequate relief;
(2) it would be extremely difficult to ascertain the amount of compensation which would afford adequate relief;
(3) the restraint is necessary to prevent a multiplicity of judicial proceedings; or
(4) the obligation arises from a trust.