def level_of_indent(state, indent):
    """
    indent: str
    precondition: `state.indent_str` is not None

    returns: the whole number of non-overlapping `state.indent_str` in `indent`
        (i.e. the indentation level where `state.indent_str` is the base unit of indentation)
    """
    return len(indent) // len(state.indent_str)