node positions do not work with link value zero in Sankey

Hello,
I'm new to the plot.ly lib but I already discovered an issue.
If there is a node with:

• no links
• only links with the value of zero

the manual positioning doesn't work anymore except if you delete the relating coordinates of this node and keep the node in the list (see third example).

Below you can find a short testing code with the generated output.

working example

import plotly.graph_objects as go
data=go.Sankey(
    arrangement = "freeform",
    node = {
        "label": ["A", "B", "C", "D", "E", "F"],
        "x": [0.2, 0.1, 0.9, 0.7, 0.3, 0.9],
        "y": [0.1, 0.9, 0.2, 0.1, 0.9, 0.9],
        'pad':100},  # 10 Pixels 
    link = {
        "source": [0, 0, 1, 4, 4, 3, 3],
        "target": [1, 3, 4, 3, 5, 2, 5],
        "value": [3, 3, 5, 4, 10, 1, 7 ]})
fig_sankey = go.Figure(data=data)
fig_sankey.show()

node with only one link with value of zero

import plotly.graph_objects as go
data=go.Sankey(
    arrangement = "freeform",
    node = {
        "label": ["A", "B", "C", "D", "E", "F"],
        "x": [0.2, 0.1, 0.9, 0.7, 0.3, 0.9],
        "y": [0.1, 0.9, 0.2, 0.1, 0.9, 0.9],
        'pad':100},  # 10 Pixels 
    link = {
        "source": [0, 0, 1, 4, 4, 3, 3],
        "target": [1, 3, 4, 3, 5, 2, 5],
        "value": [3, 3, 5, 4, 10, 0, 7 ]})
fig_sankey = go.Figure(data=data)
fig_sankey.show()

kind of working again cause coordinates of C are deleted

import plotly.graph_objects as go
data=go.Sankey(
    arrangement = "freeform",
    node = {
        "label": ["A", "B", "C", "D", "E", "F"],
        "x": [0.2, 0.1, 0.7, 0.3, 0.9],
        "y": [0.1, 0.9, 0.1, 0.9, 0.9],
        'pad':100},  # 10 Pixels 
    link = {
        "source": [0, 0, 1, 4, 4, 3, 3],
        "target": [1, 3, 4, 3, 5, 2, 5],
        "value": [3, 3, 5, 4, 10, 0, 7 ]})
fig_sankey = go.Figure(data=data)
fig_sankey.show()

まず、提供されている Python Sankey の例を実行し、1つのリンクの値がゼロの場合の自由配置を比較します。Python の図の定義からノード位置を処理するコンポーネントまで、Sankey のレンダリング経路を追跡します。リンクがないノード、または値がゼロのリンクしかないノードでも手動座標が有効なままとなり、両方のケースを対象とする回帰テストがあることを完了条件とします。