_measureArea = (...objects) => {
    objects = flatten(objects)
    // we create a preemptive cache
    const cache = cacheWithInvalidation()
    const operands = cachedGenerator(objects, cache)

    const area = measureArea(operands)
    specials.push({ cache, result: area })

    return area
  }
Measure the area of the given geometry.

@see http://paulbourke.net/geometry/polygonmesh/
@param {geom2} geometry - 2D geometry to measure
@returns {Number} area of the geometry