code: public void localVariableUse(LocalVariable localVar) {
          if (mLocalVariableTable == null) {
              addAttribute(new LocalVariableTableAttr(getConstantPool()));
          }
          mLocalVariableTable.addEntry(localVar);
      }
docs: Indicate a local variable's use information be recorded in the
  ClassFile as a debugging aid. If the LocalVariable doesn't provide
  both a start and end location, then its information is not recorded.
  This method should be called at most once per LocalVariable instance.