code: function getOptimalUpdate(component, implicit, reference) {
    if (equal(implicit, reference)) {
      return null;
    }
    if (isSingleProperty(component.schema)) {
      return reference;
    }
    var optimal = {};
    Object.keys(reference).forEach(function(key) {
      var needsUpdate = !equal(reference[key], implicit[key]);
      if (needsUpdate) {
        optimal[key] = reference[key];
      }
    });
    return optimal;
  }
docs: Returns the minimum value for a component with an implicit value to equal a
  reference value. A `null` optimal value means that there is no need for an
  update since the implicit value and the reference are equal.
  
  @param {Component} component Component of the computed value.
  @param {any}       implicit  The implicit value of the component.
  @param {any}       reference The reference value for the component.
  @return                      the minimum value making the component to equal
  the reference value.