@Override
  public int hashCode() {
    return Objects.hash(super.hashCode(), name, type, keyConstraint, valueConstraint, diskStoreName,
        redundantCopies, expirations, eviction);
  }
this sets the memory size in megabytes and the eviction type to MEMORY_SIZE

@param memorySizeMb the memory size in megabytes
@throws IllegalArgumentException if type is already set to other values. This is to prevent
        users from trying to send conflicting json attributes
        such as {type:HEAP_PERCENTAGE,memorySizeMb:100}
geode-management/src/main/java/org/apache/geode/management/configuration/Region.java