foo(int a, int b){
if (a == null or b == null){
return null
}
}

bar(int a, int b){
if (a == null and b == null){
return null
}
}


foo[StringToken]([BeginToken]int[StringToken] a[StringToken],[SimpleToken] int[StringToken] b[StringToken])[SimpleToken]{[BeginToken]
if[KeywordToken] ([BeginToken]a[StringToken] ==[SimpleToken] null[KeywordToken] or[StringToken] b[StringToken] ==[SimpleToken] null[KeywordToken])[SimpleToken]{[BeginToken]
return[KeywordToken] null[KeywordToken]
}[SimpleToken]
}[SimpleToken]

bar[StringToken]([BeginToken]int[StringToken] a[StringToken],[SimpleToken] int[StringToken] b[StringToken])[SimpleToken]{[BeginToken]
if[KeywordToken] ([BeginToken]a[StringToken] ==[SimpleToken] null[KeywordToken] and[StringToken] b[StringToken] ==[SimpleToken] null[KeywordToken])[SimpleToken]{[BeginToken]
return[KeywordToken] null[KeywordToken]
}[SimpleToken]
}[SimpleToken]
[SimpleToken]
