title: fixing missing ToUniCode map in PDF
body: <p>I have a pdf file from which I want to extract text. But because of missing toUniCode map, I am not able to do it.</p>
  
  <pre><code>./pdffonts /Users/subhashlengare/Downloads/pqr39_abc.pdf
  name                                 type              emb sub uni object ID
  ------------------------------------ ----------------- --- --- --- ---------
  ATRTHG+TT1CABt00                     TrueType          yes yes no      23  0
  VFQVYH+TT1CAEt00                     TrueType          yes yes no      19  0
  ODNMDG+TT1CAFt00                     TrueType          yes yes no      31  0
  DXGYRQ+TT1CB0t00                     TrueType          yes yes no      27  0
  VFQVYH+TT1CB1t00                     TrueType          yes yes no       7  0
  ArialMT                              TrueType          no  no  no     295  0
  NXBBUP+TT1CC0t00                     TrueType          yes yes no      53  0
  NXBBUP+TT1CC1t00                     TrueType          yes yes no      65  0
  KDGXKF+TT1CC4t00                     TrueType          yes yes no     104  0
  VRCBAT+TT1CC5t00                     TrueType          yes yes no     100  0
  QTNBCJ+TT1CC2t00                     TrueType          yes yes no      88  0
  NXBBUP+TT1CC6t00                     TrueType          yes yes no      96  0
  NXBBUP+TT1CC7t00                     TrueType          yes yes no     116  0
  NXBBUP+TT1CC8t00                     TrueType          yes yes no     128  0
  </code></pre>
  
  <p>How can we add back missing ToUniCode map, so that text extraction works well? </p>