<!-- Checkbox Column -->
    <ng-container matColumnDef="select">
      <th mat-header-cell *matHeaderCellDef>
        <mat-checkbox
          (change)="$event ? masterToggle() : null"
          [checked]="selection.hasValue() && isAllSelected()"
          [indeterminate]="selection.hasValue() && !isAllSelected()"
          [aria-label]="checkboxLabel()"
        >
        </mat-checkbox>
      </th>
      <td mat-cell *matCellDef="let row">
        <mat-checkbox
          (click)="$event.stopPropagation()"
          (change)="$event ? selection.toggle(row) : null"
          [checked]="selection.isSelected(row)"
          [aria-label]="checkboxLabel(row)"
        >
        </mat-checkbox>
      </td>
    </ng-container>

    <!-- Position Column -->
    <ng-container matColumnDef="position">
      <th mat-header-cell *matHeaderCellDef mat-sort-header>이름</th>
      <td mat-cell *matCellDef="let element">
        <app-user-item></app-user-item>
      </td>
    </ng-container>

    <!-- Name Column -->
    <ng-container matColumnDef="name">
      <th mat-header-cell *matHeaderCellDef>연락처</th>
      <td mat-cell *matCellDef="let element">{{ element.name }}</td>
    </ng-container>

    <!-- Weight Column -->
    <ng-container matColumnDef="weight">
      <th mat-header-cell *matHeaderCellDef>이메일</th>
      <td mat-cell *matCellDef="let element">{{ element.weight }}</td>
    </ng-container>

    <tr mat-header-row *matHeaderRowDef="displayedColumns"></tr>
    <tr
      mat-row
      *matRowDef="let row; columns: displayedColumns"
      (click)="selection.toggle(row)"
    ></tr>