code: def get_children(self):
          
          handle = SymbolHandle()
          check_call(_LIB.MXSymbolGetChildren(
              self.handle, ctypes.byref(handle)))
          ret = Symbol(handle=handle)
          if len(ret.list_outputs()) == 0:
              return None
          return ret
docs: Gets a new grouped symbol whose output contains
          inputs to output nodes of the original symbol.
  
          Example
          -------
          >>> x = mx.sym.Variable('x')
          >>> y = mx.sym.Variable('y')
          >>> z = mx.sym.Variable('z')
          >>> a = y+z
          >>> b = x+a
          >>> b.get_children()
          <Symbol Grouped>
          >>> b.get_children().list_outputs()
          ['x', '_plus10_output']
          >>> b.get_children().get_children().list_outputs()
          ['y', 'z']
  
          Returns
          -------
          sgroup : Symbol or None
              The children of the head node. If the symbol has no
              inputs then ``None`` will be returned.