issue(level, msg, file, line, column, startOffset, endOffset) {
        context.messages.push({level, msg, file: file || null, line: norm(line), column: norm(column), index: norm(startOffset), startOffset: norm(startOffset), endOffset: norm(endOffset)})
    }
@param {MESSAGE_LEVEL} level
@param {string} msg
@param {string} file
@param {number} line
@param {number} column
@param {number=} startOffset
@param {number=} endOffset