Changed to set up nodes_at_patch on-demand.
Changed to set up nodes_at_patch on-demand.

Carralex/landlab,cmshobe/landlab,laijingtao/landlab,landlab/landlab,ManuSchmi88/landlab,cmshobe/landlab,RondaStrauch/landlab,csherwood-usgs/landlab,landlab/landlab,landlab/landlab,csherwood-usgs/landlab,ManuSchmi88/landlab,RondaStrauch/landlab,amandersillinois/landlab,RondaStrauch/landlab,laijingtao/landlab,cmshobe/landlab,amandersillinois/landlab,Carralex/landlab,Carralex/landlab,ManuSchmi88/landlab