A find_mut query on the interval tree does not directly return references to the nodes in the tree, but
wraps the fields interval and data in an EntryMut. Only the data part can be mutably accessed
using the data method
An interval tree is a tree data structure to hold intervals.
Specifically, it allows one to efficiently find all intervals that overlap with any given interval or point.
An IntervalTreeIteratorMut is returned by Intervaltree::find_mut and iterates over the entries
overlapping the query allowing mutable access to the data D, not the Interval.