gets the actual lines of the call if multiLineSearch is true, it finds
function getFunctionCallLines(sourcesContent, filePath, functionName, lineNumber, multiLineSearch, warningHandler) {
        if(sourcesContent !==  undefined) {
            var source = Future(sourcesContent)
        } else {
            var source = options.getScriptSourceLines(filePath)
        }
        return source.catch(function(e) {
            warningHandler(e)
            return Future(undefined)

        }).then(function(fileLines) {
            if(fileLines !== undefined) {

                var startLine = findStartLine(fileLines, functionName, lineNumber)
                if(startLine === 'lineOfCodeNotFound') {
                    return Future("<line of code not found (possibly an error?)> ")

                } else if(startLine !== 'sourceNotAvailable') {
                    if(multiLineSearch) {
                        return Future(findFullSourceLine(fileLines, startLine))
                    } else {
                        return Future(fileLines[startLine].trim())
                    }
                }
            }
            // else
            return Future("<source not available>")

        })
    }