Synthetic children provider called multiple times

[4emodan]

I have implemented several synthetic children providers for Haxe language. For example, this one for Haxe's StringMap class:

class StringMapChildrenProvider:
	def __init__(self, valobj, internal_dict):
		print(f'StringMapChildrenProvider {valobj.name}')
		
		self.value = valobj
		self.ptr = self.value.GetChildMemberWithName('mPtr').deref
		
		keys = self.ptr.EvaluateExpression('keys()').GetNonSyntheticValue().GetChildMemberWithName('mPtr').deref
		
		self.items = []
		hx_iterator_for_each(keys, 'String', lambda item: self.items.append(hx_string_to_py_string(item)))
		print(f'StringMapChildrenProvider {self.value.name} keys {self.items}')
		
	def num_children(self):
		print(f'StringMapChildrenProvider {self.value.name} num_children')
		return len(self.items)
		
	def get_child_index(self, name):
		print(f'StringMapChildrenProvider {self.value.name} get_child_index {name}')
		return 0 # TODO: should probably implement this
		
	def get_child_at_index(self, index):
		print(f'StringMapChildrenProvider {self.value.name} get_child_at_index {index}')
		item = self.items[index]
		val = self.ptr.EvaluateExpression(f'get({item})').GetNonSyntheticValue()
		return val.Clone(f'{item}')
		
	def update(self):
		print(f'StringMapChildrenProvider {self.value.name} update')
		pass
	
	def has_children(self):
		print(f'StringMapChildrenProvider {self.value.name} has_children')
		return True

I put prints to see which function gets called when. And surprisingly this provider gets called several times. I'm new to lldb, but seems that it's not normal.

I set a breakpoint and see these frame variables:

And when I unfold "this" variable, this is what gets printed:

StringMapChildrenProvider packInfos
StringMapChildrenProvider packInfos keys ['"preloaderReq"', '"jetgui"', '"index"', '"tutorialSpine"', '"tutorialImage"', '"tutorialScene"', '"homeUnreq"', '"homeReq"', '"generated"', '"deploy"']
StringMapChildrenProvider packInfos update
StringMapChildrenProvider packInfos
StringMapChildrenProvider packInfos keys ['"preloaderReq"', '"jetgui"', '"index"', '"tutorialSpine"', '"tutorialImage"', '"tutorialScene"', '"homeUnreq"', '"homeReq"', '"generated"', '"deploy"']
StringMapChildrenProvider packInfos update
StringMapChildrenProvider packInfos
StringMapChildrenProvider packInfos keys ['"preloaderReq"', '"jetgui"', '"index"', '"tutorialSpine"', '"tutorialImage"', '"tutorialScene"', '"homeUnreq"', '"homeReq"', '"generated"', '"deploy"']
StringMapChildrenProvider packInfos update
Child list expansion has timed out.
StringMapChildrenProvider packInfos num_children

What could be a problem?