[Test-set_attribute] Added a unit test for set_attribute function

tests/test_set_attribute.py

+import numpy as np
+from onnx import TensorProto, helper
+
+import finn.core.onnx_exec as oxe
+import finn.custom_op.xnorpopcount as xp
+from finn.core.datatype import DataType
+from finn.core.modelwrapper import ModelWrapper
+from finn.core.utils import get_by_name
+
+def test_set_attribute():
+    mw = 8
+    mh = 8
+    pe = 4
+    simd = 4
+    wmem = mw * mh // (pe * simd)
+    nf = mh // pe
+    sf = mw // simd
+    idt = odt = wdt = DataType.BIPOLAR
+
+    inp = helper.make_tensor_value_info("inp", TensorProto.FLOAT, [1, sf, simd])
+    outp = helper.make_tensor_value_info("outp", TensorProto.FLOAT, [1, nf, pe])
+    node_inp_list = ["inp", "weights"]
+    
+    FCLayer_node = helper.make_node(
+        "StreamingFCLayer_Batch",
+        node_inp_list,
+        ["outp"],
+        domain="finn",
+        backend="",
+        code_gen_dir="",
+        executable_path="",
+        resType="ap_resource_lut()",
+        MW=0,
+        MH=mh,
+        SIMD=simd,
+        PE=pe,
+        WMEM=wmem,
+        inputDataType=idt.name,
+        weightDataType=wdt.name,
+        outputDataType=odt.name,
+    )
+    graph = helper.make_graph(
+        nodes=[FCLayer_node], name="fclayer_graph", inputs=[inp], outputs=[outp]
+    )
+
+    model = helper.make_model(graph, producer_name="fclayer-model")
+    model = ModelWrapper(model)
+
+    # test cases
+    value_to_set = "fpgadataflow"
+    model.set_attribute(FCLayer_node, "backend", value_to_set)
+    value = get_by_name(FCLayer_node.attribute, "backend")
+    assert value.s.decode('UTF-8') == value_to_set
+
+    value_to_set = mw
+    model.set_attribute(FCLayer_node, "MW", value_to_set)
+    value = get_by_name(FCLayer_node.attribute, "MW")
+    assert value.i == value_to_set
+
+    value_to_set = idt.name
+    model.set_attribute(FCLayer_node, "inputDataType", value_to_set)
+    value = get_by_name(FCLayer_node.attribute, "inputDataType")
+    assert value.s.decode('UTF-8') == value_to_set
+
+
+    
+