PACKER

Pack the 4 inputs into a package signal.
Input Ports
There's four input ports, i1,i2,i3,i4, with the type of any.
Output Ports
There's one output port o1, with type of package.
Function
Once (one of) the four input signals changed, the output package is updated.
The output package is in the form of {i1, i2, i3, i4}.