def __init__(self, context=None):
        self.context = context or {}
        self.source = None
Like `first_visible_line`, but for the center visible line.
dataset/ETHPy150Open GeekTrainer/Flask/Work/Trivia - Module 5/env/Lib/site-packages/pip/_vendor/distlib/markers.py/Evaluator.__init__--crossover with--dataset/ETHPy150Open jonathanslenders/python-prompt-toolkit/prompt_toolkit/layout/containers.py/WindowRenderInfo.center_visible_line