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

file:./
               state = STATIC
          created by   root:
            supplies   file:README.md
            supplies   file:backup.md
            supplies   file:plan.py
            supplies   step:./plan.py
            supplies   step:cp -aT README.md backup.md

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

step:./plan.py
               state = SUCCEEDED
           explained = yes
          created by   root:
            consumes   file:./
            consumes   file:plan.py
             creates   file:README.md
             creates   step:cp -aT README.md backup.md

file:README.md
               state = STATIC
          created by   step:./plan.py
            consumes   file:./
            supplies   step:cp -aT README.md backup.md

step:cp -aT README.md backup.md
               state = SUCCEEDED
          created by   step:./plan.py
            consumes   file:./
            consumes   file:README.md
             creates   file:backup.md
            supplies   file:backup.md

file:backup.md
               state = BUILT
          created by   step:cp -aT README.md backup.md
            consumes   file:./
            consumes   step:cp -aT README.md backup.md
