code: private void createCvt(FontFileReader in) throws IOException {
          TTFDirTabEntry entry = (TTFDirTabEntry)dirTabs.get("cvt ");
          if (entry != null) {
              pad4();
              seekTab(in, "cvt ", 0);
              System.arraycopy(in.getBytes((int)entry.getOffset(), (int)entry.getLength()),
                               0, output, currentPos, (int)entry.getLength());
  
              int checksum = getCheckSum(currentPos, (int)entry.getLength());
              writeULong(cvtDirOffset, checksum);
              writeULong(cvtDirOffset + 4, currentPos);
              writeULong(cvtDirOffset + 8, (int)entry.getLength());
              currentPos += (int)entry.getLength();
              realSize += (int)entry.getLength();
          } else {
              throw new IOException("Can't find cvt table");
          }
      }
docs: Copy the cvt table as is from original font to subset font
  
  @param in The input to read the CVT from
  @throws IOException Indicates a failure to read the entry