code: def check_environment_presets():
      
      presets = [x for x in os.environ.copy().keys() if x.startswith('NOVA_') or
                 x.startswith('OS_')]
      if len(presets) < 1:
          return True
      else:
          click.echo("_" * 80)
          click.echo("*WARNING* Found existing environment variables that may "
                     "cause conflicts:")
          for preset in presets:
              click.echo("  - %s" % preset)
          click.echo("_" * 80)
          return False
docs: Checks for environment variables that can cause problems with supernova