I try to do something like this:

public const List<String> METRICS = new List<String>()
        {
            SourceFile.LOC,
            SourceFile.MCCABE,
            SourceFile.NOM,
            SourceFile.NOA,
            SourceFile.FANOUT,
            SourceFile.FANIN,
            SourceFile.NOPAR,
            SourceFile.NDC,
            SourceFile.CALLS
        };

But unfortunately this doesn't work:

FileStorer.METRICS' is of type 'System.Collections.Generic.List<string>'. A const field of a reference type other than string can only be initialized with null.

How can I solve this problem?