cdm/src/main/java/ucar/nc2/iosp/grads/GradsDataDescriptorFile.java
private void addChsub(Chsub sub) {
    if (chsubs == null) {
      chsubs = new ArrayList<>();
    }
    chsubs.add(sub);
  }
private void addChsub(Chsub sub) {
    if (chsubs == null) {
      chsubs = new ArrayList<>();
    }
    chsubs.add(sub);
  }
Add a Chsub

@param sub the chsub