DataFrame merge method change Left and Right values

[asmirnov82]

System information

• OS version/distro: Windows 10
• .NET Version (eg., dotnet --info): 5.0.201

Issue

• What did you do?

I used DataFrame,Merge method with Algo Inner and Right dataframe having less rows than left dataframe

• What happened?

Right values are merged into Left columns and Left values into right columns

• What did you expect?

I expected the left values to be merged into columns "_left" suffix and right values into columns with "_right" suffix

Source code / logs

Unit test to reproduce (expect to work same way for (1,2) and (2,1)):

[Theory]
[InlineData(1, 2)]
[InlineData(2, 1)]
public void TestMerge_3(int leftCount, int rightCount)
{
DataFrame left = MakeDataFrameWithNumericColumns(leftCount, false);
DataFrameColumn leftStringColumn = new StringDataFrameColumn("String", Enumerable.Range(0, leftCount).Select(x => "Left"));
left.Columns.Insert(left.Columns.Count, leftStringColumn);

        DataFrame right = MakeDataFrameWithNumericColumns(rightCount, false);
        DataFrameColumn rightStringColumn = new StringDataFrameColumn("String", Enumerable.Range(0, rightCount).Select(x => "Right"));
        right.Columns.Insert(right.Columns.Count, rightStringColumn);

        DataFrame merge = left.Merge<int>(right, "Int", "Int", joinAlgorithm: JoinAlgorithm.Inner);

        Assert.Equal("Left", (string)merge.Columns["String_left"][0]);
        Assert.Equal("Right", (string)merge.Columns["String_right"][0]);
    }

Please paste or attach the code or logs or traces that would be helpful to diagnose the issue you are reporting.