Helper function that gathers historical patch data for use in color generation.
WARNING: This is an internal function. Its use in user code is not recommended or supported, and its signature can change in future updates without warning. Use one of the suggested functions above instead, if applicable.
patch — Patch, required
The patch whose data to retrieve.
t — int, optional
The model time for which to retrieve the patch data.
Default value: None
Return Value — num
The value of the patch property or good stocks indicated in the
patchProperty parameter. See
NetworkPlot.config() for details.