cdm/src/main/java/ucar/nc2/iosp/hdf4/HdfEos.java
private Dimension checkUnknownDims(String wantDim, List<Dimension> unknownDims, Dimension oldDim, String location) {
    for (Dimension dim : unknownDims) {
      if (dim.getShortName().equals(wantDim)) {
        int len = oldDim.getLength();
        if (len == 0) {
          dim.setUnlimited(true); // allow zero length dimension !!
        }
        dim.setLength(len); // use existing (anon) dimension
        Group parent = dim.getGroup();
        parent.addDimensionIfNotExists(dim);  // add to the parent
        unknownDims.remove(dim); // remove from list LOOK is this ok?
        log.warn("unknownDim {} length set to {}{}", wantDim, oldDim.getLength(), location);
        return dim;
      }
    }
    return null;
  }
private Dimension checkUnknownDims(String wantDim, List<Dimension> unknownDims, Dimension oldDim, String location) {
    for (Dimension dim : unknownDims) {
      if (dim.getShortName().equals(wantDim)) {
        int len = oldDim.getLength();
        if (len == 0) {
          dim.setUnlimited(true); // allow zero length dimension !!
        }
        dim.setLength(len); // use existing (anon) dimension
        Group parent = dim.getGroup();
        parent.addDimensionIfNotExists(dim);  // add to the parent
        unknownDims.remove(dim); // remove from list LOOK is this ok?
        log.warn("unknownDim {} length set to {}{}", wantDim, oldDim.getLength(), location);
        return dim;
      }
    }
    return null;
  }
look if the wanted dimension is in the  unknownDims list.