function Environment(global) {
	    this.global = global;
	    this.flags = {};
	    this.flagRegistry = {};
	    this.urlFlags = {};
	    this.populateURLFlags();
	  }
The environment contains evaluated flags as well as the registered platform.
This is always used as a global singleton and can be retrieved with
`tf.env()`.

@doc {heading: 'Environment'}