private void findPrimaryOffset() {
		primaryOffset = 0;
		for (RowLayout layout : layouts) {
			if (layout.isPrimary()) {
				return;
			}
			primaryOffset += layout.getHeight();
		}
		primaryOffset = 0;
	}
Returns the row containing the given FieldLocation.
Ghidra/Framework/Docking/src/main/java/docking/widgets/fieldpanel/support/MultiRowLayout.java