root:
             creates   file:./
             creates   file:plan.py
             creates   step:runpy ./plan.py

file:./
               state = STATIC
          created by   root:
            supplies   file:input.txt
            supplies   file:output.txt
            supplies   file:plan.py
            supplies   step:runpy ./plan.py

file:plan.py
               state = STATIC
          created by   root:
            consumes   file:./
            supplies   step:runpy ./plan.py

step:runpy ./plan.py
               state = SUCCEEDED
             env_var = STEPUP_PATH_FILTER [amended]
          created by   root:
            consumes   file:./
            consumes   file:input.txt [amended]
            consumes   file:plan.py
             creates   file:input.txt
             creates   file:output.txt
            supplies   file:output.txt [amended]

file:input.txt
               state = STATIC
          created by   step:runpy ./plan.py
            consumes   file:./
            supplies   step:runpy ./plan.py

file:output.txt
               state = BUILT
          created by   step:runpy ./plan.py
            consumes   file:./
            consumes   step:runpy ./plan.py
