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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def layer_title(layer):
 """Set the layer title according to the standards. :param layer: The layer to style. :type layer: QgsVectorLayer """

    exposure_type = layer.keywords['exposure_keywords']['exposure']
    exposure_definitions = definition(exposure_type)
    title = exposure_definitions['layer_legend_title']
    layer.setTitle(title)
    layer.keywords['title'] = title