def METHOD_NAME(self, batch: Batch, key_prefix: Optional[str] = None) -> Dict[str, Any]:
    r"""
    forward function of the GaussianKernelPosEncoder class
    Parameters:
        batch: The batch of pyg graphs
        key_prefix: The prefix to use for the input keys
    Returns:
        A dictionary of the output encodings with keys specified by `output_keys`
    """
    input_keys = self.parse_input_keys_with_prefix(key_prefix)
    on_ipu = is_running_on_ipu()
    max_num_nodes_per_graph = None
    if on_ipu:
        max_num_nodes_per_graph = self.max_num_nodes_per_graph
    attn_bias_3d, node_feature_3d = self.preprocess_3d_positions(
        batch, max_num_nodes_per_graph, on_ipu, positions_3d_key=input_keys[0]
    )
    # Return `attn_bias_3d` if the key starts with 'nodepair_'
    # Crash if the key starts with 'edge_' or 'graph_'
    # Return `node_feature_3d` otherwise
    output = {}
    for key in self.output_keys:
        if isinstance(key, str) and key.startswith("nodepair_"):
            output[key] = attn_bias_3d
        elif isinstance(key, str) and key.startswith("edge_"):
            raise ValueError("Edge encodings are not supported for this encoder")
        else:
            output[key] = node_feature_3d
    return output