class_docstr: Image to Patch Embedding
      
class_docstr_tok: ["Image","to","Patch","Embedding"]
code: def forward(self, x, mask=None):
      B, C, H, W = x.shape
      return self.proj(x)
  
imports: import math
  import paddle
  import paddle.nn
  import paddle.nn.functional
  import numpy
  from paddle.nn.initializer import Constant
  from ppdet.modeling.shape_spec import ShapeSpec
  from ppdet.core.workspace import register, serializable
  from .transformer_utils import zeros_, DropPath, Identity
label_desc: Use image node_id 4 for calling the PatchEmbed obj's underlying member method code with example usage: obj.forward(x, mask) and returns: self