paramMap = filter.parseQueryString("a=%E3%83%86%E3%82%B9%E3%83%88", "UTF-8");
        assertEquals(1, paramMap.size());
        assertEquals("テスト", paramMap.get("a")[0]);

        paramMap = filter.parseQueryString("a=%A5%C6%A5%B9%A5%C8", "EUC-JP");
        assertEquals(1, paramMap.size());
        assertEquals("テスト", paramMap.get("a")[0]);

        paramMap = filter.parseQueryString("a=%83e%83X%83g", "Shift_JIS");

#include "textflag.h"

// func Syscall6(num, a1, a2, a3, a4, a5, a6 uintptr) (r1, r2, errno uintptr)
//
// The 5th and 6th arg go at sp+16, sp+20.
// Note that frame size of 20 means that 24 bytes gets reserved on stack.
TEXT ·Syscall6(SB),NOSPLIT,$20-40
	MOVW	num+0(FP), R2	// syscall entry
	MOVW	a1+4(FP), R4
	MOVW	a2+8(FP), R5
	MOVW	a3+12(FP), R6
	MOVW	a4+16(FP), R7
	MOVW	a5+20(FP), R8
	MOVW	a6+24(FP), R9
	MOVW	R8, 16(R29)

000000e0  81 8d 00 30 81 89 02 81  81 00 db 46 7d 93 2e 12  |...0.......F}...|
000000f0  27 06 48 bc 06 28 21 ab  7e c4 b6 a2 5d fe 1e 52  |'.H..(!.~...]..R|
00000100  45 88 7a 36 47 a5 08 0d  92 42 5b c2 81 c0 be 97  |E.z6G....B[.....|
00000110  79 98 40 fb 4f 6d 14 fd  2b 13 8b c2 a5 2e 67 d8  |y.@.Om..+.....g.|
00000120  d4 09 9e d6 22 38 b7 4a  0b 74 73 2b c2 34 f1 d1  |...."8.J.ts+.4..|
00000130  93 e5 96 d9 74 7b f3 58  9f 6c 61 3c c0 b0 41 d4  |....t{.X.la<..A.|

#include "textflag.h"
#include "funcdata.h"

//
// System call support for AMD64 unixes
//

// func Syscall(trap int64, a1, a2, a3 int64) (r1, r2, err int64)
// func Syscall6(trap int64, a1, a2, a3, a4, a5, a6 int64) (r1, r2, err int64)
// Trap # in AX, args in DI SI DX, return in AX DX

TEXT	·Syscall(SB),NOSPLIT,$0-56
	CALL	runtime·entersyscall<ABIInternal>(SB)
	MOVQ	trap+0(FP), AX	// syscall entry
	MOVQ	a1+8(FP), DI

00000180  c7 ba 08 2d a7 26 75 80  1d 1d 0c 7f 01 15 6f 82  |...-.&u.......o.|
00000190  bf 5a a3 84 cd ac 91 56  cb d2 17 78 a5 b0 22 bf  |.Z.....V...x..".|
000001a0  d2 f3 1e 9f 8f f7 66 b7  a0 ec 28 f1 c5 b6 4e 24  |......f...(...N$|
000001b0  63 46 88 d2 7a 84 11 8e  ce 5d ab 5f e7 81 7d a5  |cF..z....]._..}.|
000001c0  2f df f3 a6 2d 1f d9 e1  01 80 53 cf 4f 2c be bc  |/...-.....S.O,..|

//
// See go.dev/issue/67401.
//
//go:linkname syscall_syscall6 syscall.syscall6
//go:nosplit
func syscall_syscall6(fn, a1, a2, a3, a4, a5, a6 uintptr) (r1, r2, err uintptr) {
	args := struct{ fn, a1, a2, a3, a4, a5, a6, r1, r2, err uintptr }{fn, a1, a2, a3, a4, a5, a6, r1, r2, err}
	entersyscall()
	libcCall(unsafe.Pointer(abi.FuncPCABI0(syscall6)), unsafe.Pointer(&args))
	exitsyscall()
	return args.r1, args.r2, args.err
}

	MOVD	ZR, err+48(FP)	// err
	RET

// func Syscall6(trap uintptr, a1, a2, a3, a4, a5, a6 uintptr) (r1, r2, err uintptr)
TEXT	·Syscall6(SB),NOSPLIT,$0-80
	BL	runtime·entersyscall<ABIInternal>(SB)
	MOVD	trap+0(FP), R17	// syscall entry
	MOVD	a1+8(FP), R0
	MOVD	a2+16(FP), R1
	MOVD	a3+24(FP), R2
	MOVD	a4+32(FP), R3
	MOVD	a5+40(FP), R4
	MOVD	a6+48(FP), R5
	SVC	$SYS_syscall
	BCC	ok
	MOVD	$-1, R1

//go:linkname syscall_syscall6 syscall.syscall6
func syscall_syscall6(fn, a1, a2, a3, a4, a5, a6 uintptr) (r1, r2 uintptr, err syscall.Errno)

//go:linkname syscall_syscall6X syscall.syscall6X
func syscall_syscall6X(fn, a1, a2, a3, a4, a5, a6 uintptr) (r1, r2 uintptr, err syscall.Errno)

//go:linkname syscall_syscall9 syscall.syscall9
func syscall_syscall9(fn, a1, a2, a3, a4, a5, a6, a7, a8, a9 uintptr) (r1, r2 uintptr, err syscall.Errno)

00000150  24 a5 19 e5 8e de 85 97  05 68 4f 39 d1 49 05 c9  |$........hO9.I..|
00000160  7a 54 90 29 e7 93 ec 8e  6f cc 73 73 82 7d 72 8d  |zT.)....o.ss.}r.|
00000170  4a 85 29 7f a5 53 13 26  16 b2 fa c3 ce 1f 8b ae  |J.)..S.&........|
00000180  e6 60 8c 2d b0 64 66 d4  29 7c b5 2d 1d 11 c5 09  |.`.-.df.)|.-....|
00000190  bb a5 44 c6 c8 af e6 f1  d5 f8 d9 45 97 64 7f 03  |..D........E.d..|

		var e interface{} = X(0)
		a5 := e.(I1)
		a6 := e.(I2)
		isfalse(a1 == b1)
		isfalse(a1 == b2)
		isfalse(a2 == b1)
		isfalse(a2 == b2)
		istrue(a1 == a2)
		istrue(a1 == a3)
		istrue(a1 == a4)
		istrue(a1 == a5)
		istrue(a1 == a6)
		istrue(a2 == a3)
		istrue(a2 == a4)
		istrue(a2 == a5)
		istrue(a2 == a6)
		istrue(a3 == a4)
		istrue(a3 == a5)
		istrue(a3 == a6)
		istrue(a4 == a5)