@Override
    public boolean equals(final Object obj) {
      if (!(obj instanceof MockFile)) { return false; }
      return ((MockFile) obj).path.equals(this.path) && ((MockFile) obj).length == this.length;
    }
Compute the number of bytes that overlap between the two ranges.
@param offset1 start of range1
@param length1 length of range1
@param offset2 start of range2
@param length2 length of range2
@return the number of bytes in the overlap range
common/src/test/org/apache/hive/common/util/MockFileSystem.java