diff --git a/projects/some-charts-lib/package.json b/projects/some-charts-lib/package.json
index 609adcd..9c4ae0b 100644
--- a/projects/some-charts-lib/package.json
+++ b/projects/some-charts-lib/package.json
@@ -1,6 +1,6 @@
 {
   "name": "some-charts",
-  "version": "0.0.369-beta.19",
+  "version": "0.0.369-beta.20",
   "scripts": {
     "build-dev": "webpack --env=development && tsc --declaration --project tsconfig.lib.json",
     "build": "webpack --env=production && tsc --declaration --project tsconfig.lib.json",
diff --git a/projects/some-charts-lib/src/chart/axis/axis-base.ts b/projects/some-charts-lib/src/chart/axis/axis-base.ts
index 54e7646..dbbe8f2 100644
--- a/projects/some-charts-lib/src/chart/axis/axis-base.ts
+++ b/projects/some-charts-lib/src/chart/axis/axis-base.ts
@@ -6,7 +6,6 @@ import {Chart} from "../chart";
 import {MajorTicksGenerator, MinorTicksGenerator, Tick} from "./ticks";
 import {DataTransformation, NumericPoint, NumericRange, Range, Size} from '../../geometry';
 import zipWith from 'lodash-es/zipWith';
-import merge from "lodash-es/merge";
 import {AxisOrientation} from "./axis-orientation";
 import {LabelsLayout} from "./labels-layout";
 import {LayerId} from "../../layer-id";
diff --git a/projects/some-charts-lib/src/chart/axis/ticks/date/generators/minor/lvl1/minor-lvl1-time-unit-ticks-generator.ts b/projects/some-charts-lib/src/chart/axis/ticks/date/generators/minor/lvl1/minor-lvl1-time-unit-ticks-generator.ts
index 2d54953..b4f44f6 100644
--- a/projects/some-charts-lib/src/chart/axis/ticks/date/generators/minor/lvl1/minor-lvl1-time-unit-ticks-generator.ts
+++ b/projects/some-charts-lib/src/chart/axis/ticks/date/generators/minor/lvl1/minor-lvl1-time-unit-ticks-generator.ts
@@ -3,9 +3,7 @@ import {TimeUnit} from "../../../time-unit";
 import * as moment from "moment";
 import { MinorTicksGenerator } from "../../../../minor-ticks-generator";
 import { Tick } from "../../../../tick";
-import {LabeledTick} from "../../../../labeled-tick";
 import {MinorDateTick} from "../../../minor-date-tick";
-import {MinorLvl1DaysTicksGenerator} from "./minor-lvl1-days-ticks-generator";
 
 export abstract class MinorLvl1TimeUnitTicksGenerator implements MinorTicksGenerator<Date> {
 
diff --git a/projects/some-charts-lib/src/chart/axis/ticks/date/generators/minor/lvl2/minor-lvl2-time-unit-ticks-generator.ts b/projects/some-charts-lib/src/chart/axis/ticks/date/generators/minor/lvl2/minor-lvl2-time-unit-ticks-generator.ts
index 18658e2..041bab4 100644
--- a/projects/some-charts-lib/src/chart/axis/ticks/date/generators/minor/lvl2/minor-lvl2-time-unit-ticks-generator.ts
+++ b/projects/some-charts-lib/src/chart/axis/ticks/date/generators/minor/lvl2/minor-lvl2-time-unit-ticks-generator.ts
@@ -3,9 +3,7 @@ import {TimeUnit} from "../../../time-unit";
 import * as moment from "moment";
 import { MinorTicksGenerator } from "../../../../minor-ticks-generator";
 import { Tick } from "../../../../tick";
-import {LabeledTick} from "../../../../labeled-tick";
 import {MinorDateTick} from "../../../minor-date-tick";
-import {MinorLvl2DaysTicksGenerator} from "./minor-lvl2-days-ticks-generator";
 
 export abstract class MinorLvl2TimeUnitTicksGenerator implements MinorTicksGenerator<Date> {
 
diff --git a/projects/some-charts-lib/src/chart/axis/ticks/labeled-tick.ts b/projects/some-charts-lib/src/chart/axis/ticks/labeled-tick.ts
index c4a776a..c91ebc3 100644
--- a/projects/some-charts-lib/src/chart/axis/ticks/labeled-tick.ts
+++ b/projects/some-charts-lib/src/chart/axis/ticks/labeled-tick.ts
@@ -1,6 +1,6 @@
 import {Tick} from "./tick";
 
-export class LabeledTick<T = number> extends Tick<T>{
+export class LabeledTick<T extends Object = number> extends Tick<T>{
   label: string;
 
   constructor(value: T, length: number, index: number, label: string) {
diff --git a/projects/some-charts-lib/src/chart/axis/ticks/major-ticks-generator.ts b/projects/some-charts-lib/src/chart/axis/ticks/major-ticks-generator.ts
index 5549e38..d985b8f 100644
--- a/projects/some-charts-lib/src/chart/axis/ticks/major-ticks-generator.ts
+++ b/projects/some-charts-lib/src/chart/axis/ticks/major-ticks-generator.ts
@@ -1,7 +1,7 @@
 import {Range} from "../../../index";
 import { Tick } from "./tick";
 
-export abstract class MajorTicksGenerator<T> {
+export abstract class MajorTicksGenerator<T extends Object > {
 
   protected tickHeight: number;
 
diff --git a/projects/some-charts-lib/src/chart/axis/ticks/minor-ticks-generator.ts b/projects/some-charts-lib/src/chart/axis/ticks/minor-ticks-generator.ts
index e0ed85f..7e04731 100644
--- a/projects/some-charts-lib/src/chart/axis/ticks/minor-ticks-generator.ts
+++ b/projects/some-charts-lib/src/chart/axis/ticks/minor-ticks-generator.ts
@@ -1,7 +1,7 @@
 import {Range} from "../../../index";
 import { Tick } from "./tick";
 
-export interface MinorTicksGenerator<T> {
+export interface MinorTicksGenerator<T extends Object> {
   /**
    * Generates minor ticks in specified range.
    * @param {Range} range - data range.