code: function UnaryConstraint(v, strength) {
    UnaryConstraint.superConstructor.call(this, strength);
    this.myOutput = v;
    this.satisfied = false;
    this.addConstraint();
  }
docs: /* --- *
  U n a r y   C o n s t r a i n t
  --- 
  Abstract superclass for constraints having a single possible output
  variable.