title: Possible Unhandled Promise Rejection (id:0) Warning
body: <p>I am getting the following warning message when my AsyncStorage Item is empty <strong>"Possible Unhandled Promise Rejection (id:0)"</strong> So my question is: How can I handle a promise rejection?</p>
  
  <p><strong>My code:</strong></p>
  
  <pre><code>componentDidMount() {
          try {
              // This warning only appears when 'connections' item is empty
              AsyncStorage.getItem('connections').then((token) =&gt; {
                  token = JSON.parse(token);
  
                  const getSectionData = (dataBlob, sectionId) =&gt; dataBlob[sectionId];
                  const getRowData = (dataBlob, sectionId, rowId) =&gt; dataBlob[`${rowId}`];
  
                  const ds = new ListView.DataSource({
                      rowHasChanged: (r1, r2) =&gt; r1 !== r2,
                      sectionHeaderHasChanged: (s1, s2) =&gt; s1 !== s2,
                      getSectionData,
                      getRowData,
                  });
  
                  const {dataBlob, sectionIds, rowIds} = this.formatData(token);
  
                  this.setState({
                      dataSource: ds.cloneWithRowsAndSections(dataBlob, sectionIds, rowIds),
                  });
              });
          }catch(error) {
              console.log(error);
          }
      }
  </code></pre>