Missing method 'envelop'

Hi,

In your docs you write there is a function tree.envelop(begin, end). However, if I try to call it I get:
AttributeError: 'IntervalTree' object has no attribute 'envelop'
And listing of all methods returns:

['__and__',
 '__class__',
 '__contains__',
 '__delattr__',
 '__delitem__',
 '__dir__',
 '__eq__',
 '__format__',
 '__ge__',
 '__getattribute__',
 '__getitem__',
 '__gt__',
 '__iand__',
 '__init__',
 '__ior__',
 '__isub__',
 '__iter__',
 '__ixor__',
 '__le__',
 '__len__',
 '__lt__',
 '__ne__',
 '__new__',
 '__or__',
 '__rand__',
 '__reduce__',
 '__reduce_ex__',
 '__repr__',
 '__ror__',
 '__rsub__',
 '__rxor__',
 '__setattr__',
 '__setitem__',
 '__sizeof__',
 '__str__',
 '__sub__',
 '__subclasshook__',
 '__xor__',
 '_add_boundaries',
 '_from_iterable',
 '_hash',
 '_remove_boundaries',
 'add',
 'addi',
 'append',
 'appendi',
 'begin',
 'chop',
 'clear',
 'containsi',
 'copy',
 'difference',
 'difference_update',
 'discard',
 'discardi',
 'end',
 'extend',
 'find_nested',
 'from_tuples',
 'intersection',
 'intersection_update',
 'is_empty',
 'isdisjoint',
 'items',
 'iter',
 'merge_equals',
 'merge_overlaps',
 'overlaps',
 'overlaps_point',
 'overlaps_range',
 'pop',
 'print_structure',
 'range',
 'remove',
 'remove_envelop',
 'remove_overlap',
 'removei',
 'score',
 'search',
 'slice',
 'span',
 'split_overlaps',
 'symmetric_difference',
 'symmetric_difference_update',
 'union',
 'update',
 'verify']

It shows all mentions methods from your documention, expect envelop. Is it simply not implemented or what happend to this function?

Thanks a lot for your help.

Best,

Joachim

Nevermind, I think I use the old 2.X version.

In v3.0.2, the method exists:

intervaltree/intervaltree/intervaltree.py

Line 802 in 9cf0018

def envelop(self, begin, end=None):

Using v2.x would definitely explain why the docs are different.