code: def _get_conda_channels(conda_bin):
      
      channels = ["bioconda", "conda-forge"]
      out = []
      config = yaml.safe_load(subprocess.check_output([conda_bin, "config", "--show"]))
      for c in channels:
          present = False
          for orig_c in config.get("channels") or []:
              if orig_c.endswith((c, "%s/" % c)):
                  present = True
                  break
          if not present:
              out += ["-c", c]
      return out
docs: Retrieve default conda channels, checking if they are pre-specified in config.
  
      This allows users to override defaults with specific mirrors in their .condarc