Postgrex.close-exclamation-mark

You're seeing just the function close-exclamation-mark, go back to Postgrex module for more information.
Link to this function

close!(conn, query, opts \\ [])

View Source

Specs

close!(conn(), Postgrex.Query.t(), [option()]) :: :ok

Closes an (extended) prepared query and returns :ok or raises Postgrex.Error if there was an error. See close/3.