constructor(text, options, metadata) {
		this.text = text
		// If assigning the `{}` default value is moved to the arguments above,
		// code coverage would decrease for some weird reason.
		this.options = options || {}
		this.metadata = metadata

		// Iteration tristate.
		this.state = 'NOT_READY'

		this.regexp = new RegExp(VALID_PHONE_NUMBER_WITH_EXTENSION, 'ig')
	}
Extracts a parseable phone number including any opening brackets, etc.
@param  {string} text - Input.
@return {object} `{ ?number, ?startsAt, ?endsAt }`.