.. py:function:: create_when_branch(pattern, position = None, size = None, display = DK.GRAPHICAL, label_width = 0)

   
   Create an intermediate structure for a when branch.

   The graphical properties are expressed 1/100th of mm.

   They are considered if and only if the owning when block
   has a graphical representation.

   :Parameters:

       **pattern** : :obj:`EX`
           Value of the branch.

       **position** : :obj:`Tuple`\[:class:`python:float`, :class:`python:float`], default: :data:`python:None`
           Position of the action.

       **size** : :obj:`Tuple`\[:class:`python:float`, :class:`python:float`], default: :data:`python:None`
           Size of the action.

       **display** : :obj:`DK`, default: :obj:`GRAPHICAL`
           Layout of the action.

       **label_width** : :class:`python:int`
           Optional width of the label containing the pattern.

   :Returns:

       :obj:`WhenBranch`
           ..













   ..
       !! processed by numpydoc !!