code: def build_placeholders(self):
      num_supports = 1
      self.placeholders = {
          "support": [
              tf.sparse_placeholder(tf.float32)
              for _ in range(num_supports)
          ],
          "features": tf.sparse_placeholder(
              tf.float32,
              shape=tf.constant(self.features[2], dtype=tf.int64),
          ),
          "labels": tf.placeholder(
              tf.float32, shape=(None, self.labels.shape[1])
          ),
          "labels_mask": tf.placeholder(tf.int32),
          "dropout": tf.placeholder_with_default(0.0, shape=()),
          # helper variable for sparse dropout
          "num_features_nonzero": tf.placeholder(tf.int32),
      }
  
file_path: OpenNE/src/openne/gcn/gcnAPI.py
imports: import numpy
  from .utils import *
  from .None import models
  import time
  import scipy.sparse
  import tensorflow
label_desc: Use image node_id 3 for calling the GCN obj's underlying member method code with example usage: obj.build_placeholders() without return types