public RegionFactory<K, V> setConcurrencyLevel(int concurrencyLevel) {
    attrsFactory.setConcurrencyLevel(concurrencyLevel);
    return this;
  }
Sets the concurrency level tof the next {@code RegionAttributes} created. This value is used in
initializing the map that holds the entries.

@param concurrencyLevel the concurrency level of the entry map
@return a reference to this RegionFactory object
@throws IllegalArgumentException if concurrencyLevel is nonpositive
@see AttributesFactory#setConcurrencyLevel
geode-core/src/main/java/org/apache/geode/cache/RegionFactory.java