Add a missing declaration
@@ -27,6 +27,7 @@ Number = Union[int, float]
class EnvLoopObserver(abc.ABC):
"""An interface for collecting metrics/counters in EnvironmentLoop."""
+ @abc.abstractmethod
def observe_first(self, env: dm_env.Environment, timestep: dm_env.TimeStep
) -> None:
"""Observes the initial state."""
