do not send multiple streams for the same path

spec/Section 3 -- Type System.md

@@ -2126,10 +2126,7 @@ scalar UUID @specifiedBy(url: "https://tools.ietf.org/html/rfc4122")
 ### @defer
 
 ```graphql
-directive @defer(
-  label: String
-  if: Boolean! = true
-) on FRAGMENT_SPREAD | INLINE_FRAGMENT
+directive @defer(if: Boolean! = true) on FRAGMENT_SPREAD | INLINE_FRAGMENT
 ```
 
 The `@defer` directive may be provided for fragment spreads and inline fragments
@@ -2144,7 +2141,7 @@ delivered in a subsequent response. `@include` and `@skip` take precedence over
 query myQuery($shouldDefer: Boolean) {
   user {
     name
-    ...someFragment @defer(label: "someLabel", if: $shouldDefer)
+    ...someFragment @defer(if: $shouldDefer)
   }
 }
 fragment someFragment on User {
@@ -2161,20 +2158,11 @@ fragment someFragment on User {
   [related note](#note-088b7)). When `false`, fragment will not be deferred and
   data will be included in the initial response. Defaults to `true` when
   omitted.
-- `label: String` - May be used by GraphQL clients to identify the data from
-  responses and associate it with the corresponding defer directive. If
-  provided, the GraphQL service must add it to the corresponding payload.
-  `label` must be unique label across all `@defer` and `@stream` directives in a
-  document. `label` must not be provided as a variable.
 
 ### @stream
 
 ```graphql
-directive @stream(
-  label: String
-  if: Boolean! = true
-  initialCount: Int = 0
-) on FIELD
+directive @stream(if: Boolean! = true, initialCount: Int = 0) on FIELD
 ```
 
 The `@stream` directive may be provided for a field of `List` type so that the
@@ -2186,7 +2174,7 @@ responses. `@include` and `@skip` take precedence over `@stream`.
 query myQuery($shouldStream: Boolean) {
   user {
     friends(first: 10) {
-      nodes @stream(label: "friendsStream", initialCount: 5, if: $shouldStream)
+      nodes @stream(initialCount: 5, if: $shouldStream)
     }
   }
 }
@@ -2198,11 +2186,6 @@ query myQuery($shouldStream: Boolean) {
   [related note](#note-088b7)). When `false`, the field will not be streamed and
   all list items will be included in the initial response. Defaults to `true`
   when omitted.
-- `label: String` - May be used by GraphQL clients to identify the data from
-  responses and associate it with the corresponding stream directive. If
-  provided, the GraphQL service must add it to the corresponding payload.
-  `label` must be unique label across all `@defer` and `@stream` directives in a
-  document. `label` must not be provided as a variable.
 - `initialCount: Int` - The number of list items the service should return as
   part of the initial response. If omitted, defaults to `0`. A field error will
   be raised if the value of this argument is less than `0`.

spec/Section 5 -- Validation.md

@@ -474,7 +474,7 @@ unambiguous. Therefore any two field selections which might both be encountered
 for the same object are only valid if they are equivalent.
 
 During execution, the simultaneous execution of fields with the same response
-name is accomplished by {MergeSelectionSets()} and {CollectFields()}.
+name is accomplished by {CollectFields()}.
 
 For simple hand-written GraphQL, this rule is obviously a clear developer error,
 however nested fragments can make this difficult to detect manually.
@@ -1605,71 +1605,6 @@ subscription sub {
 }
 ```
 
-### Defer And Stream Directive Labels Are Unique
-
-** Formal Specification **
-
-- Let {labelValues} be an empty set.
-- For every {directive} in the document:
-  - Let {directiveName} be the name of {directive}.
-  - If {directiveName} is "defer" or "stream":
-    - For every {argument} in {directive}:
-      - Let {argumentName} be the name of {argument}.
-      - Let {argumentValue} be the value passed to {argument}.
-      - If {argumentName} is "label":
-        - {argumentValue} must not be a variable.
-        - {argumentValue} must not be present in {labelValues}.
-        - Append {argumentValue} to {labelValues}.
-
-**Explanatory Text**
-
-The `@defer` and `@stream` directives each accept an argument "label". This
-label may be used by GraphQL clients to uniquely identify response payloads. If
-a label is passed, it must not be a variable and it must be unique within all
-other `@defer` and `@stream` directives in the document.
-
-For example the following document is valid:
-
-```graphql example
-{
-  dog {
-    ...fragmentOne
-    ...fragmentTwo @defer(label: "dogDefer")
-  }
-  pets @stream(label: "petStream") {
-    name
-  }
-}
-
-fragment fragmentOne on Dog {
-  name
-}
-
-fragment fragmentTwo on Dog {
-  owner {
-    name
-  }
-}
-```
-
-For example, the following document will not pass validation because the same
-label is used in different `@defer` and `@stream` directives.:
-
-```raw graphql counter-example
-{
-  dog {
-    ...fragmentOne @defer(label: "MyLabel")
-  }
-  pets @stream(label: "MyLabel") {
-    name
-  }
-}
-
-fragment fragmentOne on Dog {
-  name
-}
-```
-
 ### Stream Directives Are Used On List Fields
 
 **Formal Specification**