function ChainWrapper(subject, explicitChain) {
    this._wrappedValue = subject;
    this._explicitChain = explicitChain;
  }
The chain wrapper constructor.

@ignore
@param  {string}       subject               The string to be wrapped.
@param  {boolean}      [explicitChain=false] A boolean that indicates if the chain sequence is explicit or implicit.
@return {ChainWrapper}                       Returns a new instance of `ChainWrapper`
@constructor