for i, part := range parts {
		if partNumber == part.Number {
			return i
		}
	}
	return -1
}

// objectPartIndexNums returns the index of the specified part number.
// Returns -1 if the part cannot be found.
func objectPartIndexNums(parts []int, partNumber int) int {
	for i, part := range parts {
		if part != 0 && partNumber == part {
			return i
		}
	}
	return -1
}