function enableDebug() {
  this.logger.warn('Enabling debug mode for shim!')
  this._debug = true
  this._wrapped = []
}
Enables debugging mode of the shim.

In debug mode the shim will track all methods that it wraps so they can be
unwrapped. This should _not_ be done in production code because a lot more
objects are held onto in memory.

@private
@memberof Shim.prototype