dbus-introspect is a compiled Lisp function in `dbus.el'.

(dbus-introspect BUS SERVICE PATH)

Return all interfaces and sub-nodes of SERVICE,
registered at object path PATH at bus BUS.

BUS is either a Lisp symbol, `:system' or `:session', or a string
denoting the bus address. SERVICE must be a known service name,
and PATH must be a valid object path. The last two parameters
are strings. The result, the introspection data, is a string in
XML format.