Remove _emptyList from fn2.dart

sky/specs/style-guide.md

 Sky Style Guide
 ===============
 
 In general, follow our [Design Principles](design.md) for all code.
 
 
 Dart
 ----
 
 In general, follow the [Dart style
@@ skipping 33 matching lines @@
 come immediately after the constructors.
 
 Be consistent in the order of members. If a constructor lists a bunch
 of fields, then those fields should declared be in the same order, and
 any code that operates on all of them should operate on them in the
 same order (unless the order matters).
 
 
 All variables and arguments are typed; don't use "var", "dynamic", or
 "Object" in any case where you could figure out the actual type.
-Always specialise generic types where possible. Even for ```[]``` and
-```{}``` literals, include the types.
+Always specialise generic types where possible.
 
 Aim for a line length of 80 characters, but go over if breaking the
 line would make it less readable.
 
 Only use => when the result fits on a single line.
 
 When using ```{ }``` braces, put a space or a newline after the open
 brace and before the closing brace. (If the black is empty, the same
 space will suffice for both.)
 
@@ skipping 31 matching lines @@
 > ```
 
 
 C++
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 Java
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