GET and POST should not be the only HTTP methods implemented in XMLHttpRequest for Workers.

GET(""): GET(null bytes), Content-Type: null
GET(null): GET(null bytes), Content-Type: null
GET("123"): GET(null bytes), Content-Type: null
POST(""): POST(0 bytes), Content-Type: text/plain;charset=UTF-8
POST(null): POST(0 bytes), Content-Type: null
POST("123"): POST(3 bytes), Content-Type: text/plain;charset=UTF-8
PUT(""): PUT(0 bytes), Content-Type: text/plain;charset=UTF-8
PUT(null): PUT(0 bytes), Content-Type: null
PUT("123"): PUT(3 bytes), Content-Type: text/plain;charset=UTF-8
DELETE(""): DELETE(0 bytes), Content-Type: text/plain;charset=UTF-8
DELETE(null): DELETE(null bytes), Content-Type: null
DELETE("123"): DELETE(3 bytes), Content-Type: text/plain;charset=UTF-8
HEAD(""): HEAD(null bytes), Content-Type: null
HEAD(null): HEAD(null bytes), Content-Type: null
HEAD("123"): HEAD(null bytes), Content-Type: null
WKFOOBAR(""): WKFOOBAR(0 bytes), Content-Type: text/plain;charset=UTF-8
WKFOOBAR(null): WKFOOBAR(null bytes), Content-Type: null
WKFOOBAR("123"): WKFOOBAR(3 bytes), Content-Type: text/plain;charset=UTF-8
SEARCH(""): SEARCH(0 bytes), Content-Type: text/plain;charset=UTF-8
SEARCH(null): SEARCH(null bytes), Content-Type: null
SEARCH("123"): SEARCH(3 bytes), Content-Type: text/plain;charset=UTF-8
DONE