const isEndIndexBiggerThanStartIndex = endIndexOfDeletion > startIndexOfDeletion;
const isEndIndexEqualToStartIndexAndCoversCustomLine = endIndexOfDeletion === startIndexOfDeletion
&& this._orderedCustomLines[startIndexOfDeletion].lineNumber >= fromLineNumber
&& this._orderedCustomLines[startIndexOfDeletion].lineNumber <= toLineNumber;