code: def gelu(x):
      """Implementation of the gelu activation function.
      https://arxiv.org/abs/1606.08415
      """
      return x * 0.5 * (1.0 + paddle.erf(x / math.sqrt(2.0)))
  
imports: import paddle
  import paddle.nn
  import paddle.nn.functional
  from paddle.nn import ReLU, Swish, GELU
  import math
  from ppdet.core.workspace import register
  from ..shape_spec import ShapeSpec
label_desc: Use image node_id 1 for calling a global function with example usage: gelu(x) and returns: unknown