SOP Class Common Extended Negotiation sub-item (0x57). PS3.7 Annex D.3.3.6.
Associates a SOP class with its service class and optionally lists related general SOP classes that should also be accepted during negotiation.
@type t() :: %Dimse.Pdu.SopClassCommonExtendedNegotiation{ related_general_sop_class_uids: [String.t()] | nil, service_class_uid: String.t() | nil, sop_class_uid: String.t() | nil }