Examples from Quickstart result in AttributeError

[pmaen]

The first example from https://github.com/biosustain/co/blob/c2be2cf358bccb7ee775b52feeab78f948a61f27/docs/quickstart.rst

>>> from co import Component
>>> from co.mutation import *
>>> hello = Component('Hello X!')
>>> hello.seq
Seq('Hello X!', Alphabet())
>>> hello_world = hello.mutate([Mutation(6, 1, 'world')])
>>> hello_world.seq
Seq('Hello world!', Alphabet())

results in the following output/error:

Hello X!
/home/paul/.local/lib/python3.10/site-packages/Bio/Seq.py:1754: BiopythonDeprecationWarning: myseq.tomutable() is deprecated; please use MutableSeq(myseq) instead.
  warnings.warn(
Traceback (most recent call last):
  File "/home/paul/Desktop/testfile.py", line 5, in <module>
    hello_world = hello.mutate([Mutation(6, 1, 'world')])
  File "/home/paul/.local/lib/python3.10/site-packages/co/component.py", line 237, in mutate
    affected_features = features.overlap(mutation.position, mutation.end)
  File "/home/paul/.local/lib/python3.10/site-packages/co/feature.py", line 288, in overlap
    intersect = set(super(ComponentFeatureSet, self).overlap(start, end))
  File "/home/paul/.local/lib/python3.10/site-packages/co/feature.py", line 115, in overlap
    for f in sorted(self._features.search(start, end + 1)):
AttributeError: 'IntervalTree' object has no attribute 'search'