Java

public class Solution { public static void main(String[] args) throws Exception {

    TestDataEmptyArray tea=new TestDataEmptyArray();

    try
    {
        if(tea.get_array().length==0)
        {
            throw new Exception("Cannot get the minimum value index from an empty sequence");
        }
    }
    catch(Exception ex)
    {
        if(ex.getMessage() == "Cannot get the minimum value index from an empty sequence")
        {
            //System.out.print("OK");
        }
    }

    TestDataUniqueValues tduv = new TestDataUniqueValues();

    var temp=tduv.get_array();

    int minidx=0;

    for (int i=0; i<temp.length;i++) 
    {
        if(temp[i]<temp[minidx])
        {
            minidx=i;
        }
    }

    if(minidx == tduv.get_expected_result())
    {
        //System.out.print("OK");
    }

    TestDataExactlyTwoDifferentMinimums tdtdm=new TestDataExactlyTwoDifferentMinimums();

    temp=tdtdm.get_array();

    var res= -1;

    int minItem=999999999;

    for (int i=0; i<temp.length;i++) 
    {
        if(temp[i]<minItem)
        {
            minItem=temp[i];
            res=i;
        }
    }

    var tres = tdtdm.get_expected_result();

    if(tres==res)
    {
        System.out.print("OK");
    }
}

}

class TestDataEmptyArray { public int[] get_array() { return new int[0]; } }

class TestDataUniqueValues { public int[] get_array() { return new int[]{3,2,6,9,6}; }

public int get_expected_result()
{
    return 1;
}

}

class TestDataExactlyTwoDifferentMinimums { public int[] get_array() { return new int[]{3,2,6,9,2,6}; }

public int get_expected_result()
{
    return 1;
}

}

python

    class TestDataEmptyArray:
            def get_array():
                    return []

class TestDataUniqueValues:
        def get_array():
                return [9, 1]

        def get_expected_result():
                return 1

class TestDataExactlyTwoDifferentMinimums():
        def get_array():
                return[1,1,2]

        def get_expected_result():
                return 0

JAVA 8

static Random rand = new Random();

public static class TestDataEmptyArray
{
    public static int[] get_array()
    {
        return new int[0];
    }

}

public static class TestDataUniqueValues
{
    static int[] arr;

    public static int[] get_array()
    {
        int bound = rand.nextInt(100) + 2;
        arr = new int[bound];
        Set<Integer> set = new HashSet<>();

        while (set.size() < bound)
        {
            set.add(rand.nextInt(100000));
        }

        arr = set.stream().mapToInt(Integer::intValue).toArray();

        return arr;
    }

    public static int get_expected_result()
    {
        int min_index = 0;

        for (int i = 1; i < arr.length; i++)
        {
            if (arr[i] < arr[min_index])
            {
                min_index = i;
            }
        }

        return min_index;
    }
}

public static class TestDataExactlyTwoDifferentMinimums
{
    static int[] arr;

    public static int[] get_array()
    {
        int bound = rand.nextInt(100) + 2;
        arr = new int[bound];
        Set<Integer> set = new HashSet<>();

        while (set.size() < bound - 1)
        {
            set.add(rand.nextInt(100000));
        }

        arr = set.stream().mapToInt(Integer::intValue).toArray();

        Arrays.sort(arr);
        arr[arr.length - 1] = arr[0];

        return arr;
    }

    public static int get_expected_result()
    {
        int min_index = 0;

        for (int i = 1; i < arr.length; i++)
        {
            if (arr[i] < arr[min_index])
            {
                min_index = i;
            }
        }

I wanted to go off track and use abstract classes, but everything ended up being more straightforward than I expected, haha.

        return min_index;
    }
}

Where is C# for this problem?