src/interface.js
function is (constructor, value) {
  return value !== null && (value.constructor === constructor || value instanceof constructor);
}
function is (constructor, value) {
  return value !== null && (value.constructor === constructor || value instanceof constructor);
}
function is ( constructor , value ) { return value !== null && ( value . constructor === constructor || value instanceof constructor ) ; }
Determines if 'value' is an instance of 'constructor'.

@private

@param  {object} constructor
@param  {*} value
@return {boolean}
Determines if value is an instance of constructor .