cdm/src/main/java/ucar/nc2/Group.java
public boolean remove(Dimension d) {
    if (immutable) throw new IllegalStateException("Cant modify");
    return d != null && dimensions.remove(d);
  }
public boolean remove(Dimension d) {
    if (immutable) throw new IllegalStateException("Cant modify");
    return d != null && dimensions.remove(d);
  }
Remove an Dimension : uses the dimension hashCode to find it.

@param d remove this Dimension.
@return true if was found and removed