ffi_native_invalid_multiple_annotations    
                  Native functions and fields must have exactly one @Native annotation.
Description
#
                    The analyzer produces this diagnostic when there is more than one Native
                    annotation on a single declaration.
                  
Example
#
                    The following code produces this diagnostic because the function f has
                    two Native annotations associated with it:
                  
                      dart
                      
                  import 'dart:ffi';
@Native<Int32 Function(Int32)>()
@Native<Int32 Function(Int32)>(isLeaf: true)
external int f(int v);
                      
                      
                      
                    Common fixes
#Remove all but one of the annotations:
                      dart
                      
                  import 'dart:ffi';
@Native<Int32 Function(Int32)>(isLeaf: true)
external int f(int v);