tensorflow/core/ops/compat/ops_history_v1/ConcatV2.pbtxt

op {
  name: "ConcatV2"
  input_arg {
    name: "values"
    type_attr: "T"
    number_attr: "N"
  }
  input_arg {
    name: "axis"
    type_attr: "Tidx"
  }
  output_arg {
    name: "output"
    type_attr: "T"
  }
  attr {
    name: "N"
    type: "int"
    has_minimum: true
    minimum: 2
  }
  attr {
    name: "T"
    type: "type"
  }
  attr {
    name: "Tidx"
    type: "type"
    default_value {
      type: DT_INT32
    }
    allowed_values {
      list {
        type: DT_INT32
        type: DT_INT64
      }
    }
  }
}