void expectStringOrSymbol ( Node n , JSType type , String msg ) { if ( ! type . matchesStringContext ( ) && ! type . matchesSymbolContext ( ) ) { mismatch ( n , msg , type , STRING_SYMBOL ) ; } }
Expect the type to be a string or symbol or a type convertible to a string . If the expectation is not met issue a warning at the provided node s source code position .