[DDC-2757] Update documentation with regard to manually closing the EntityManager when an Exception occurs.

docs/en/reference/transactions-and-concurrency.rst

@@ -70,7 +70,6 @@ looks like this:
         $em->getConnection()->commit();
     } catch (Exception $e) {
         $em->getConnection()->rollback();
-        $em->close();
         throw $e;
     }
 
@@ -81,14 +80,12 @@ require an active transaction. Such methods will throw a
 ``TransactionRequiredException`` to inform you of that
 requirement.
 
-A more convenient alternative for explicit transaction demarcation
+A more convenient alternative for explicit transaction demarcation is the use
-is the use of provided control abstractions in the form of
+of provided control abstractions in the form of
-``Connection#transactional($func)`` and
+``Connection#transactional($func)`` and ``EntityManager#transactional($func)``.
-``EntityManager#transactional($func)``. When used, these control
+When used, these control abstractions ensure that you never forget to rollback
-abstractions ensure that you never forget to rollback the
+the transaction, in addition to the obvious code reduction. An example that is
-transaction or close the ``EntityManager``, apart from the obvious
+functionally equivalent to the previously shown code looks as follows:
-code reduction. An example that is functionally equivalent to the
-previously shown code looks as follows:
 
 .. code-block:: php
 
@@ -104,8 +101,8 @@ previously shown code looks as follows:
 The difference between ``Connection#transactional($func)`` and
 ``EntityManager#transactional($func)`` is that the latter
 abstraction flushes the ``EntityManager`` prior to transaction
-commit and also closes the ``EntityManager`` properly when an
+commit and rolls back the transaction when an
-exception occurs (in addition to rolling back the transaction).
+exception occurs.
 
 Exception Handling
 ~~~~~~~~~~~~~~~~~~