pub unsafe extern "C" fn switch_core_session_send_dtmf_string(
session: *mut switch_core_session_t,
dtmf_string: *const c_char,
) -> switch_status_tpub unsafe extern "C" fn switch_core_session_send_dtmf_string(
session: *mut switch_core_session_t,
dtmf_string: *const c_char,
) -> switch_status_t