private String getInputDataTypeName(PcodeOp op, int inIndex, DataType preferredDt) {
		if (preferredDt != null && !Undefined.isUndefined(preferredDt)) {
			return preferredDt.getDisplayName();
		}
		Varnode vn = op.getInput(inIndex);
		DataType dt = null;
		if (vn != null) {
			dt = vn.getHigh().getDataType();
		}
		if (dt != null) {
			return dt.getDisplayName();
		}
		return "BAD";
	}
Try to find the PcodeOp representing the call the user has selected
@param program is the Program
@param tokenAtCursor is the point in the window the user has selected
@return the PcodeOp or null
Ghidra/Features/Decompiler/src/main/java/ghidra/app/plugin/core/decompile/actions/OverridePrototypeAction.java