src/streamlink/plugin/api/validate.py
def contains(string):
    """Checks if the string value contains another string."""
    def contains_str(value):
        validate(text, value)
        if string not in value:
            raise ValueError("'{0}' does not contain '{1}'".format(value, string))
        return True

    return contains_str
def contains(string):
    """Checks if the string value contains another string."""
    def contains_str(value):
        validate(text, value)
        if string not in value:
            raise ValueError("'{0}' does not contain '{1}'".format(value, string))
        return True

    return contains_str
Checks if the string value contains another string.