message: Update callbacks documentation for custom callback implementers, so they know callbacks might not get called every batch.
diff: @@ -675,6 +675,10 @@ class Callback(object):
  Subclasses should override for any actions to run.
  + Note that if the `steps_per_execution` argument to `compile` in
  + `tf.keras.Model` is set to `N`, this method will only be called every `N`
  + batches.
  +
  Arguments:
  batch: Integer, index of batch within the current epoch.
  logs: Dict, contains the return value of `model.train_step`. Typically,
  @@ -691,6 +695,10 @@ class Callback(object):
  Subclasses should override for any actions to run.
  + Note that if the `steps_per_execution` argument to `compile` in
  + `tf.keras.Model` is set to `N`, this method will only be called every `N`
  + batches.
  +
  Arguments:
  batch: Integer, index of batch within the current epoch.
  logs: Dict. Aggregated metric results up until this batch.
  @@ -708,6 +716,10 @@ class Callback(object):
  Subclasses should override for any actions to run.
  + Note that if the `steps_per_execution` argument to `compile` in
  + `tf.keras.Model` is set to `N`, this method will only be called every `N`
  + batches.
  +
  Arguments:
  batch: Integer, index of batch within the current epoch.
  logs: Dict, contains the return value of `model.test_step`. Typically,
  @@ -725,6 +737,10 @@ class Callback(object):
  Subclasses should override for any actions to run.
  + Note that if the `steps_per_execution` argument to `compile` in
  + `tf.keras.Model` is set to `N`, this method will only be called every `N`
  + batches.
  +
  Arguments:
  batch: Integer, index of batch within the current epoch.
  logs: Dict. Aggregated metric results up until this batch.
  @@ -737,6 +753,10 @@ class Callback(object):
  Subclasses should override for any actions to run.
  + Note that if the `steps_per_execution` argument to `compile` in
  + `tf.keras.Model` is set to `N`, this method will only be called every `N`
  + batches.
  +
  Arguments:
  batch: Integer, index of batch within the current epoch.
  logs: Dict, contains the return value of `model.predict_step`,
  @@ -751,6 +771,10 @@ class Callback(object):
  Subclasses should override for any actions to run.
  + Note that if the `steps_per_execution` argument to `compile` in
  + `tf.keras.Model` is set to `N`, this method will only be called every `N`
  + batches.
  +
  Arguments:
  batch: Integer, index of batch within the current epoch.
  logs: Dict. Aggregated metric results up until this batch.
  