code: function sanityCheck(pred) {
  	var key;
  	var keysFound = 0;
  
  	/* Let's just do a bit of extra sanity checking, can't hurt */
  	for (var val in pred) {
  		key = val;
  		keysFound++;
  	}
  
  	mod_assert.ok(keysFound === 0 || keysFound === 1);
  
  	if (keysFound > 0) {
  		mod_assert.ok(krillOps[key]);
  	}
  
  	return ({
  		nbKeys: keysFound,
  		key: key
  	});
  }
docs: /*
  Verifies a few basic assertions about the predicate object "pred".
  
  Inputs:
  - pred: The predicate for which to verify basic assertions.
  
  Output:
  - Returns an object of the following form:
  {
  nbKeys: numberOfKeysInPredicate,
  key: rootKeyOfPredicate
  }
  
  where "numberOfKeysInPredicate"" is an integer with the value 0 (empty
  predicate) or 1, and "rootKeyOfPredicate" is a string that represents
  the root key of the predicate.