code: def merge(inputs, mode="sum", concat_axis=-1, name=None):
      """
      Functional merge. Only use this method if you are defining a graph model.
      Used to merge a list of input nodes into a single output node (NOT layers!),
      following some merge mode.
  
      # Arguments
      inputs: A list of node instances. Must be more than one node.
      mode: Merge mode. String, must be one of: 'sum', 'mul', 'concat', 'ave', 'cos',
            'dot', 'max', 'sub', 'div', 'min'. Default is 'sum'.
      concat_axis: Int, axis to use when concatenating nodes.
                   Only specify this when merge mode is 'concat'.
                   Default is -1, meaning the last axis of the input.
      name: String to set the name of the functional merge.
            If not specified, its name will by default to be a generated string.
      """
      return Merge(mode=mode, concat_axis=concat_axis, name=name)(
          list(inputs)
      )
  
imports: import zoo.pipeline.api.autograd
  from zoo.feature.image import ImageSet
  from zoo.feature.text import TextSet
  from zoo.feature.common import FeatureSet
  from zoo.pipeline.api.keras.base import ZooKerasLayer
  from zoo.pipeline.api.keras.utils import *
  from bigdl.nn.layer import Layer
  from zoo.common.utils import callZooFunc
label_desc: Use image node_id 1 for calling a global function with example usage: merge(inputs, mode, concat_axis, name) and returns: Merge