index.js
function Layer(name, fn) {
  this.length = fn.length;
  this.name = name;
  this.fn = fn;
}
function Layer(name, fn) {
  this.length = fn.length;
  this.name = name;
  this.fn = fn;
}
function Layer ( name , fn ) { this . length = fn . length ; this . name = name ; this . fn = fn ; }
Representation of a single middleware layer.

@constructor
@param {String} name Identification of the middleware.
@param {Function} fn Middleware function.
@param {Mixed} context Execution context of the function.
@api private
Representation of a single middleware layer .