docstr: Test initialize gRPCProxyRequest with healthz service method.
  
  When the gRPCProxyRequest is initialized with healthz service method, calling
  is_route_request should return false and calling is_health_request
  should return true.
docstr_tok: ["Test","initialize","gRPCProxyRequest","with","healthz","service","method",".","When","the","gRPCProxyRequest","is","initialized","with","healthz","service","method",",","calling","is_route_request","should","return","false","and","calling","is_health_request","should","return","true","."]
code: def test_calling_healthz_method(self):
      """Test initialize gRPCProxyRequest with healthz service method.
  
      When the gRPCProxyRequest is initialized with healthz service method, calling
      is_route_request should return false and calling is_health_request
      should return true.
      """
      context = FakeGrpcContext()
      request_proto = serve_pb2.HealthzRequest()
      service_method = "/ray.serve.RayServeAPIService/Healthz"
      proxy_request = gRPCProxyRequest(
          request_proto=request_proto,
          context=context,
          service_method=service_method,
          stream=False,
      )
      assert isinstance(proxy_request, ProxyRequest)
      assert proxy_request.is_route_request is False
      assert proxy_request.is_health_request is True
  
imports: import pickle
  from unittest.mock import MagicMock
  import pytest
  from ray.serve._private.common import StreamingHTTPRequest, gRPCRequest
  from ray.serve._private.proxy_request_response import ASGIProxyRequest, ProxyRequest, gRPCProxyRequest
  from ray.serve._private.test_utils import FakeGrpcContext
  from ray.serve.generated import serve_pb2
label_desc: Use image node_id 2 for calling the TestgRPCProxyRequest obj's underlying member method code with example usage: obj.test_calling_healthz_method() without return types