pub unsafe extern "C" fn PhidgetFrequencyCounter_setOnCountChangeHandler(
ch: PhidgetFrequencyCounterHandle,
fptr: PhidgetFrequencyCounter_OnCountChangeCallback,
ctx: *mut c_void,
) -> PhidgetReturnCodepub unsafe extern "C" fn PhidgetFrequencyCounter_setOnCountChangeHandler(
ch: PhidgetFrequencyCounterHandle,
fptr: PhidgetFrequencyCounter_OnCountChangeCallback,
ctx: *mut c_void,
) -> PhidgetReturnCode