parameters: (self)
docstring: Calculate the first timestamp across all devices.
docstring_summary: Calculate the first timestamp across all devices.
docstring_tokens: Calculate the first timestamp across all devices .
function: def _calculate_t0(self):
      """Calculate the first timestamp across all devices."""
      t0s = [t0 for t0 in six.itervalues(self._t0s) if t0 is not None]
      self._t0 = min(t0s) if t0s else None
function_tokens: def _calculate_t0 ( self ) : t0s = [ t0 for t0 in six . itervalues ( self . _t0s ) if t0 is not None ] self . _t0 = min ( t0s ) if t0s else None