cdm/src/main/java/ucar/ma2/Range.java
public Range compact() throws InvalidRangeException {
    if (stride == 1) return this;
    int first = first() / stride;           // LOOK WTF ?
    int last = first + length() - 1;
    return new Range(name, first, last, 1);
  }
public Range compact() throws InvalidRangeException {
    if (stride == 1) return this;
    int first = first() / stride;           // LOOK WTF ?
    int last = first + length() - 1;
    return new Range(name, first, last, 1);
  }
Create a new Range by compacting this Range by removing the stride.
first = first/stride, last=last/stride, stride=1.

@return compacted Range
@throws InvalidRangeException elements must be nonnegative, 0 <= first <= last