Add consume_batch_id() convenience method to sil.Writer class.

rattail/sil/writer.py

@@ -34,6 +34,7 @@ from .._version import __version__
 from ..core import Object
 from ..gpc import GPC
 from rattail.files import temp_path
+from rattail.sil import batches
 
 
 __all__ = ['Writer']
@@ -62,6 +63,12 @@ class Writer(Object):
         kwargs.setdefault('suffix', '.sil')
         return temp_path(**kwargs)
 
+    def consume_batch_id(self, source='RATAIL'):
+        """
+        Consume and return a SIL-compatible batch ID.
+        """
+        return batches.consume_batch_id(source)
+
     def val(self, value):
         """
         Returns a string version of ``value``, suitable for inclusion within a