import {GroupMark} from '../marks/marktypes';

export default function(role, style, name, dataRef, interactive, encode, marks, layout) {
  return {
    type: GroupMark,
    name: name,
    role: role,
    style: style,
    from: dataRef,
    interactive: interactive || false,
    encode: encode,
    marks: marks,
    layout: layout
  };
}

import {GroupMark} from '../marks/marktypes';

export default function(role, style, name, dataRef, interactive, encode, marks) {
  return {
    type: GroupMark,
    name: name,
    role: role,
    style: style,
    from: dataRef,
    interactive: interactive || false,
    encode: encode,
    marks: marks
  };
}

--- 
+++ 
@@ -1,6 +1,6 @@
 import {GroupMark} from '../marks/marktypes';
 
-export default function(role, style, name, dataRef, interactive, encode, marks) {
+export default function(role, style, name, dataRef, interactive, encode, marks, layout) {
   return {
     type: GroupMark,
     name: name,
@@ -9,6 +9,7 @@
     from: dataRef,
     interactive: interactive || false,
     encode: encode,
-    marks: marks
+    marks: marks,
+    layout: layout
   };
 }
Update guide group util to include layout option.
