This problem involves finding the number of unique multisets formed from an array such that the bitwise XOR of all elements in the multiset is a prime number. The challenge lies in handling duplicates and efficiently counting multisets rather than sequences or subsets.

Key Points:

Multisets vs Subsets: Unlike regular subsets, multisets allow repeated elements. For elements that appear multiple times, the count of possible selections ranges from zero to their frequency, i.e., f + 1 choices per element.

XOR Behavior with Multiplicity: Adding an element an even number of times to the XOR results in no change, while an odd number of times flips the XOR by that element's value. Thus, the parity of the count chosen for each element affects the XOR outcome.

Dynamic Programming Approach: We use a DP array indexed by XOR values, where dp[x] counts the number of multisets with XOR x. For each unique element, we split the choices into two groups: those with even counts and those with odd counts, and update the DP accordingly.

Prime Check: After processing all elements, we sum the counts of multisets whose XOR is prime. Efficient prime checking with a sieve up to the maximum XOR value (8192 here) optimizes the solution.

Modulo Arithmetic: Since the number of multisets can be very large, we take all counts modulo 10^9 + 7.

This approach ensures that the counting respects multiset properties and efficiently computes the required total under given constraints.