function _getRelayedCallSender() private pure returns (address payable result) {
  // We need to read 20 bytes (an address) located at array index msg.data.length - 20. In memory, the array
  // is prefixed with a 32-byte length value, so we first add 32 to get the memory read index. However, doing
  // so would leave the address in the upper 20 bytes of the 32-byte word, which is inconvenient and would
  // require bit shifting. We therefore subtract 12 from the read index so the address lands on the lower 20
  // bytes. This can always be done due to the 32-byte prefix.

  // The final memory read index is msg.data.length - 20 + 32 - 12 = msg.data.length. Using inline assembly is the
  // easiest/most-efficient way to perform this operation.

  // These fields are not accessible from assembly
  bytes memory array = msg.data;
  uint256 index = msg.data.length;

  // solhint-disable-next-line no-inline-assembly
  assembly {
    // Load the 32 bytes word from memory with the address on the lower 20 bytes, and mask those.
    result := and(
      mload(add(array, index)),
      0xffffffffffffffffffffffffffffffffffffffff
    )
  }
  return result;
}