.class_1 {
    position: absolute;
    top: 0;
    right: 0;
    bottom: 0;
    left: 0;
}
.class_2 {
    position: absolute;
    top: 0;
    bottom: 0;
}.class_1, .class_2 {
    position: absolute;
    top: 0;
    bottom: 0;
}
.class_1 {
    right: 0;
    left: 0;
} 
  
  .class_1 {
    @extend .class_2;
    right: 0;
    left: 0;
}
.class_2 {
    position: absolute;
    top: 0;
    bottom: 0;
}%position {
    position: absolute;
    top: 0;
    bottom: 0;
}
.class_1 {
    @extend %position;
    right: 0;
    left: 0;
}
.class_2 {
    @extend %position;
}