This function takes:

• the grain supervisor pid
• short name receiver
• short name sender It send sends a pull to receiver as if it came from sender. receiver needs to be an existing grain in the recipe. sender can be an existing grain or made up.

This function takes:

• the grain supervisor pid
• short name sender It send sends a pull to predecessors of sender sender needs to be an existing grain in the recipe and alive.

Inject pull_with_tag to all predecessors of short_sender

Inject pull_with_tag to receiver as if it was issued by short_sender

This function takes:

• the grain supervisor pid
• short name receiver
• short name sender
• a message msg It send sends a push to receiver with msg as content as if it came from sender. receiver needs to be an existing grain in the recipe. sender can be an existing grain or made up.