code: 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>")
  
          })
      }
docs: gets the actual lines of the call if multiLineSearch is true, it finds