Merge pull request #2215 from OceanParcels/using_AdvectionRK4_for_ref_kernel_signature

Using AdvectionRK4 for reference of Kernel signature check

Author: erikvansebille

parcels/kernel.py

@@ -10,6 +10,7 @@
 
 from parcels.application_kernels.advection import (
     AdvectionAnalytical,
+    AdvectionRK4,
     AdvectionRK45,
 )
 from parcels.basegrid import GridType
@@ -24,7 +25,6 @@
     _raise_time_extrapolation_error,
 )
 from parcels.tools.warnings import KernelWarning
-from tests.common_kernels import DoNothing
 
 if TYPE_CHECKING:
     from collections.abc import Callable
@@ -69,7 +69,7 @@ def __init__(
         for f in pyfuncs:
             if not isinstance(f, types.FunctionType):
                 raise TypeError(f"Argument pyfunc should be a function or list of functions. Got {type(f)}")
-            _assert_same_function_signature(f, ref=DoNothing, context="Kernel")
+            _assert_same_function_signature(f, ref=AdvectionRK4, context="Kernel")
 
         if len(pyfuncs) == 0:
             raise ValueError("List of `pyfuncs` should have at least one function.")