code: def setup_previous_omero_env(self, olddir, savevarsfile):
          
          env = self.get_environment(savevarsfile)
  
          def addpath(varname, p):
              if not os.path.exists(p):
                  raise Exception("%s does not exist!" % p)
              current = env.get(varname)
              if current:
                  env[varname] = p + os.pathsep + current
              else:
                  env[varname] = p
  
          olddir = os.path.abspath(olddir)
          lib = os.path.join(olddir, "lib", "python")
          addpath("PYTHONPATH", lib)
          bin = os.path.join(olddir, "bin")
          addpath("PATH", bin)
          self.old_env = env
docs: Create a copy of the current environment for interacting with the
          current OMERO server installation