docs: function ifMarkLineHasOnlyDim(dimIndex, fromCoord, toCoord, coordSys) {
      var otherDimIndex = 1 - dimIndex;
      var dimName = coordSys.dimensions[dimIndex];
      return isInifinity(fromCoord[otherDimIndex]) && isInifinity(toCoord[otherDimIndex])
          && fromCoord[dimIndex] === toCoord[dimIndex] && coordSys.getAxis(dimName).containData(fromCoord[dimIndex]);
  }