title: Material UI Select Field multiselect
body: <p>I tried several times the example given in the documentation. but it didn't work well for me.
  can any one help me....
  this is the code</p>
  
  <pre><code>import React, {Component} from 'react';
  import SelectField from 'material-ui/SelectField';
  import MenuItem from 'material-ui/MenuItem';
  
  const names = [
    'Oliver Hansen',
    'Van Henry',
    'April Tucker',
    'Ralph Hubbard',
    'Omar Alexander',
    'Carlos Abbott',
    'Miriam Wagner',
    'Bradley Wilkerson',
    'Virginia Andrews',
    'Kelly Snyder',
  ];
  
  /**
   * `SelectField` can handle multiple selections. It is enabled with the `multiple` property.
   */
  export default class SelectFieldExampleMultiSelect extends Component {
    state = {
      values: [],
    };
  
    handleChange = (event, index, values) =&gt; this.setState({values});
  
    menuItems(values) {
      return names.map((name) =&gt; (
        &lt;MenuItem
          key={name}
          insetChildren={true}
          checked={values &amp;&amp; values.indexOf(name) &gt; -1}
          value={name}
          primaryText={name}
        /&gt;
      ));
    }
  
    render() {
      const {values} = this.state;
      return (
        &lt;SelectField
          multiple={true}
          hintText="Select a name"
          value={values}
          onChange={this.handleChange}
        &gt;
          {this.menuItems(values)}
        &lt;/SelectField&gt;
      );
    }
  }
  </code></pre>
  
  <p><a href="http://www.material-ui.com/#/components/select-field" rel="noreferrer">http://www.material-ui.com/#/components/select-field</a></p>
  
  <p>the select property works but it doesnt select multiple options. when i check the states.value it only includes a single value not a array of values</p>