class Aps:
    """Aps dictionary to be included in an APNS payload.

    Args:
        alert: A string or a ``messaging.ApsAlert`` instance (optional).
        badge: A number representing the badge to be displayed with the message (optional).
        sound: Name of the sound file to be played with the message or a
            ``messaging.CriticalSound`` instance (optional).
        content_available: A boolean indicating whether to configure a background update
            notification (optional).
        category: String identifier representing the message type (optional).
        thread_id: An app-specific string identifier for grouping messages (optional).
        mutable_content: A boolean indicating whether to support mutating notifications at
            the client using app extensions (optional).
        custom_data: A dict of custom key-value pairs to be included in the Aps dictionary
            (optional).
    """

    def __init__(self, alert=None, badge=None, sound=None, content_available=None, category=None,
                 thread_id=None, mutable_content=None, custom_data=None):
        self.alert = alert
        self.badge = badge
        self.sound = sound
        self.content_available = content_available
        self.category = category
        self.thread_id = thread_id
        self.mutable_content = mutable_content
        self.custom_data = custom_data