IsConnectionFailedErr checks if the error is a network connection attempt from the SDK fails.

IsEndorsementMismatchErr checks if the error is a mismatch.

NewTargetPeersResolver create and make map from array for faster find element.

SubscribeEventBlock - subscription to events without pass blocks.

Events stores data about block subscription without gaps.

TargetPeersResolver for filter peers after discoveryService find them - choose only peer from array.