title: 'Cannot find name' in Typescript class constructor
body: <p>I am getting a 'Cannot find name' error when I inject a service into a class by inserting the imported name into the arguments of the constructor. This has happen a few times to me now and I can't figure out what fixes it. Any light shed on this would be much appreciated. Here is my example:</p>
  
  <pre><code>import { Component } from '@angular/core';
  import { Injectable } from '@angular/core';
  import { Http, Response } from '@angular/http';
  import { _ } from 'lodash';
  import { RatesService } from '../../services/RatesService';
  import { NavController } from 'ionic-angular';
  import { Currencies } from '../../models/currencies.ts';
  
  @Component({
      selector: 'page-rates',
      templateUrl: 'rates.html'
  })
  
  export class Rates {
  
  constructor(public navCtrl: NavController,
          private ratesService: RatesService,
          private currencies: Currencies) { }
  }
  </code></pre>
  
  <p>'Currencies' causes the error</p>