/// <summary>
        /// Obtain the original source code file and line number for the given
        /// IL offset in a method identified by a unique metadata token.
        /// </summary>
        /// <param name="methodMetadataToken"></param>
        /// <param name="ilOffset"></param>
        /// <returns></returns>
        /// <remarks>
        /// Metadata token is stored in the PDB file for each method. Additionally
        /// it can always be retrieved from MethodInfo via reflection. Exception
        /// report saves a meatdata token for each method in the stack trace.
        /// </remarks>
        public SourceLocation GetSourceLoc(int methodMetadataToken, int ilOffset)
        {
            IDiaSymbol symMethod;

            _session.findSymbolByToken((uint)methodMetadataToken, SymTagEnum.SymTagFunction, out symMethod);

            var rvaMethod = symMethod.relativeVirtualAddress;

            rvaMethod += (uint)ilOffset;

            IDiaEnumLineNumbers lineNumbers;

            _session.findLinesByRVA(rvaMethod, 1, out lineNumbers);

            foreach (IDiaLineNumber ln in lineNumbers)
            {
                var sourceFile = ln.sourceFile;
                return(new SourceLocation()
                {
                    LineNumber = ln.lineNumber, SourceFile = (sourceFile == null) ? null : sourceFile.fileName
                });
            }

            return(null);
        }