code: protected void checkCobolSourceFile(final File cobolSourceFile)
              throws IOException {
          if (cobolSourceFile == null) {
              throw new IOException("You must provide a COBOL source file");
          }
          if (!cobolSourceFile.exists()) {
              throw new IOException("COBOL source  file " + cobolSourceFile
                      + " not found");
          }
      }
docs: make sure the COBOL file is valid.
  
  @param cobolSourceFile the COBOL source file
  @throws IOException if file cannot be located