function name: NewSliceEncoder
   0.case
     *ast.ExprStmt -> *ast.CallExpr -> *ast.SelectorExpr 	 [timeType e timeInstr]
     *ast.ReturnStmt 	 [e]
   1.case
     *ast.ExprStmt -> *ast.CallExpr -> *ast.SelectorExpr 	 [escapeStringType e stringInstr]
      	 [ptrEscapeStringToBuf]
     *ast.ReturnStmt 	 [e]

