Allow focus(), blur(), clear(), isFocused() function as Input's instance method.
import { Input } from 'react-universal-ui';
/*after get instance from "ref" (e.g. myInput)*/
<Input ref={(instance) => { this.myInput = instance; }} {...otherProps}/>
/*it's possible to call:
* - this.myInput.focus();
* - this.myInput.blur();
* - this.myInput.clear();
* - this.myInput.isFocused();
* like we could with ReactNative's [TextInput]
* */