==(x, y)

  Generic equality operator. Falls back to ===. Should be implemented for all types with a notion of equality, based on the abstract value
  that an instance represents. For example, all numeric types are compared by numeric value, ignoring type. Strings are compared as
  sequences of characters, ignoring encoding. 
<...>

  ==(a::AbstractString, b::AbstractString) -> Bool

  Test whether two strings are equal character by character (technically, Unicode code point by code point).

julia> s1 = Base.AnnotatedString("abc def", [(1:1, :x => :y)])
"abc def"

julia> s2 = "abc def"
"abc def"

julia> s1 == s2
false