Arul has a binary array(^{\text{∗}}) (a) of length (n). He will take all subsequences(^{\text{†}}) of length (k) ((k) is odd) of this array and find their median.(^{\text{‡}}) What is the sum of all these values? As this sum can be very large, output it modulo (10^9 + 7). In other words, print the remainder of this sum when divided by (10^9 + 7). (^{\text{∗}})A binary array is an array consisting only of zeros and ones. (^{\text{†}})An array (b) is a subsequence of an array (a) if (b) can be obtained from (a) by the deletion of several (possibly, zero or all) elements. Subsequences don't have to be contiguous. (^{\text{‡}})The median of an array of odd length (k) is the (\frac{k+1}{2})-th element when sorted. The first line contains a single integer (t) ((1 \leq t \leq 10^4)) — the number of test cases. The first line of each test case contains two integers (n) and (k) ((1 \leq k \leq n \leq 2 \cdot 10^5), (k) is odd ) — the length of the array and the length of the subsequence, respectively. The second line of each test case contains (n) integers (a_i) ((0 \leq a_i \leq 1)) — the elements of the array. It is guaranteed that sum of (n) over all test cases does not exceed (2 \cdot 10^5). For each test case, print the sum modulo (10^9 + 7). In the first test case, there are four subsequences of (1,0,0,1) with length (k=3): (1,0,0): median (= 0). (1,0,1): median (= 1). (1,0,1): median (= 1). (0,0,1): median (= 0). In the second test case, all subsequences of length (1) have median (1), so the answer is (5).