src/transformers/models/graphormer/modeling_graphormer.py/GraphormerDecoderHead/__init__
class GraphormerDecoderHead:    def __init__(self, embedding_dim, num_classes):
        super().__init__()
        """num_classes should be 1 for regression, or the number of classes for classification"""
        self.lm_output_learned_bias = nn.Parameter(torch.zeros(1))
        self.classifier = nn.Linear(embedding_dim, num_classes, bias=False)
        self.num_classes = num_classes