This file contains unit tests for the LBIJungle fitness estimator in the cassiopeia.tools module. It tests the functionality of the LBIJungle class on a small tree to ensure that fitness estimates are calculated correctly and make sense based on the tree structure.
The file defines a single test class TestLBIJungle which inherits from unittest.TestCase. This class contains two test methods: test_small_tree and test_raises_error_if_leaf_name_startswith_underscore.