graph_def2.py

node {
  name: "Variable/Assign"
  op: "Assign"
  input: "Variable"
  input: "a"
  attr {
    key: "T"
    value {
      type: DT_FLOAT
    }
  }
  attr {
    key: "use_locking"
    value {
      b: true
    }
  }
  attr {
    key: "validate_shape"
    value {
      b: true
    }
  }
}
node {
  name: "Variable/read"
  op: "Identity"
  input: "Variable"
  attr {
    key: "T"
    value {
      type: DT_FLOAT
    }
  }
}