
class DataModelAdapter(object) :

    def __init__(self, data) :
        self._data = data
        self._children = set()
        self._parent = None
        pass

    def numChildren(self) :
        return len(self._children)

    def hasData(self) :
        return self._data is not None

    def getData(self, key) :
        if key in self._data :
            return self._data[key]
        return None

    def addChild(self, child) :
        child.setParent(self)
        self._children.add(child)

    def setParent(self, parent) :
        self._parent = parent

    def parent(self) :
        return self._parent


class DataModelAdapter(object) :

    def __init__(self, data) :
        self._data = data
        self._children = set()
        self._parent = None
        pass

    def numChildren(self) :
        return len(self._children)

    def hasData(self) :
        return self._data is not None

    def getData(self, key) :
        if key in self._data :
            return self._data[key]
        return None

    def addChild(self, child) :
        child.setParent(self)
        self._children.add(child)

    def child(self, row) :
        children_list = [c for c in self._children]
        return children_list[row]

    def setParent(self, parent) :
        self._parent = parent

    def parent(self) :
        return self._parent

Add child(); TODO: test this
Add child(); TODO: test this

  
  class DataModelAdapter(object) :
  
      def __init__(self, data) :
          self._data = data
          self._children = set()
          self._parent = None
          pass
  
      def numChildren(self) :
          return len(self._children)
  
      def hasData(self) :
          return self._data is not None
  
      def getData(self, key) :
          if key in self._data :
              return self._data[key]
          return None
  
      def addChild(self, child) :
          child.setParent(self)
          self._children.add(child)
  
+     def child(self, row) :
+         children_list = [c for c in self._children]
+         return children_list[row]
+ 
      def setParent(self, parent) :
          self._parent = parent
  
      def parent(self) :
          return self._parent
  
Add child(); TODO: test this
## Code Before:

class DataModelAdapter(object) :

    def __init__(self, data) :
        self._data = data
        self._children = set()
        self._parent = None
        pass

    def numChildren(self) :
        return len(self._children)

    def hasData(self) :
        return self._data is not None

    def getData(self, key) :
        if key in self._data :
            return self._data[key]
        return None

    def addChild(self, child) :
        child.setParent(self)
        self._children.add(child)

    def setParent(self, parent) :
        self._parent = parent

    def parent(self) :
        return self._parent

## Instruction:
Add child(); TODO: test this
## Code After:

class DataModelAdapter(object) :

    def __init__(self, data) :
        self._data = data
        self._children = set()
        self._parent = None
        pass

    def numChildren(self) :
        return len(self._children)

    def hasData(self) :
        return self._data is not None

    def getData(self, key) :
        if key in self._data :
            return self._data[key]
        return None

    def addChild(self, child) :
        child.setParent(self)
        self._children.add(child)

    def child(self, row) :
        children_list = [c for c in self._children]
        return children_list[row]

    def setParent(self, parent) :
        self._parent = parent

    def parent(self) :
        return self._parent
