Failed to get the list of documents bound to a given sheet

{{velocity}}
#set ($sheetReference = $services.model.createDocumentReference('xwiki', 'Blog', 'BlogPostSheet'))
$services.sheet.getDocuments($sheetReference)
{{/velocity}}

Caused by: org.apache.velocity.exception.MethodInvocationException: Invocation of method 'getDocuments' in  class com.xpn.xwiki.internal.sheet.scripting.SheetScriptService threw exception java.lang.ClassCastException: [Ljava.lang.Object; cannot be cast to [Ljava.lang.String; at xwiki:Sandbox.FF[line 2, column 17]
	at org.apache.velocity.runtime.parser.node.ASTMethod.handleInvocationException(ASTMethod.java:243)
	at org.apache.velocity.runtime.parser.node.ASTMethod.execute(ASTMethod.java:187)
	at org.apache.velocity.runtime.parser.node.ASTReference.execute(ASTReference.java:280)
	at org.apache.velocity.runtime.parser.node.ASTReference.render(ASTReference.java:369)
	at org.apache.velocity.runtime.parser.node.SimpleNode.render(SimpleNode.java:342)
	at org.xwiki.velocity.internal.DefaultVelocityEngine.evaluate(DefaultVelocityEngine.java:228)
	... 115 more
Caused by: java.lang.ClassCastException: [Ljava.lang.Object; cannot be cast to [Ljava.lang.String;
	at com.xpn.xwiki.internal.sheet.AbstractSheetBinder.getDocuments(AbstractSheetBinder.java:141)
	at com.xpn.xwiki.internal.sheet.scripting.SheetScriptService.getDocuments(SheetScriptService.java:175)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:601)
	at org.apache.velocity.util.introspection.UberspectImpl$VelMethodImpl.doInvoke(UberspectImpl.java:395)
	at org.apache.velocity.util.introspection.UberspectImpl$VelMethodImpl.invoke(UberspectImpl.java:384)
	at org.apache.velocity.runtime.parser.node.ASTMethod.execute(ASTMethod.java:173)
	... 119 more