swapObject = function swapObject(indexA, indexB, o) {
    var copy = clone(o);
    var properties = Object.getOwnPropertyNames(copy);
    if (properties.includes(indexA) && properties.includes(indexB)) {
      var tmp = copy[indexA];
      copy[indexA] = copy[indexB];
      copy[indexB] = tmp;
    }
    return copy;
  }
Subtracts its second argument from its first argument.

@func
@memberOf R
@since v0.1.0
@category Math
@sig Number -> Number -> Number
@param {Number} a The first value.
@param {Number} b The second value.
@return {Number} The result of `a - b`.
@see R.add
@example

     R.subtract(10, 8); //=> 2

     const minus5 = R.subtract(R.__, 5);
     minus5(17); //=> 12

     const complementaryAngle = R.subtract(90);
     complementaryAngle(30); //=> 60
     complementaryAngle(72); //=> 18