Generalize stream only kernel

There exists a create_stream_pull_only_kernel. This could be generalized for all Access patterns

lbmpy/updatekernels.py

 import numpy as np
 import sympy as sp
+import warnings
 
 from lbmpy.fieldaccess import StreamPullTwoFieldsAccessor
 from lbmpy.methods.abstractlbmethod import LbmCollisionRule
@@ -58,9 +59,23 @@ def create_stream_only_kernel(stencil, numpy_arr=None, src_field_name="src", dst
                               generic_layout='numpy', generic_field_type=np.float64, accessor=None):
     """Creates a stream kernel, without collision.
 
-    For parameters see function ``create_stream_pull_collide_kernel``
+    Args:
+        stencil: lattice Boltzmann stencil which is used
+        numpy_arr: numpy array which containes the pdf field data. If no numpy array is provided the symbolic field
+                   accesses are created with 'Field.create_generic'. Otherwise 'Field.create_from_numpy_array' is used.
+        src_field_name: name of the source field.
+        dst_field_name: name of the destination field.
+        generic_layout: data layout. for example 'fzyx' of 'zyxf'.
+        generic_field_type: field data type.
+        accessor: Field accessor which is used to create the update rule. See 'fieldaccess.PdfFieldAccessor'
+
+    Returns:
+        AssignmentCollection of the stream only update rule
     """
 
+    if accessor is None:
+        accessor = StreamPullTwoFieldsAccessor()
+
     dim = len(stencil[0])
     if numpy_arr is None:
         src = Field.create_generic(src_field_name, dim, index_shape=(len(stencil),),
@@ -81,6 +96,8 @@ def create_stream_pull_only_kernel(stencil, numpy_arr=None, src_field_name="src"
 
     For parameters see function ``create_stream_pull_collide_kernel``
     """
+    warnings.warn("This function is depricated. Please use create_stream_only_kernel. If no PdfFieldAccessor is "
+                  "provided to this function a standard StreamPullTwoFieldsAccessor is used ", DeprecationWarning)
     return create_stream_only_kernel(stencil, numpy_arr=numpy_arr, src_field_name=src_field_name,
                                      dst_field_name=dst_field_name, generic_layout=generic_layout,
                                      generic_field_type=generic_field_type, accessor=StreamPullTwoFieldsAccessor())