@VisibleForTesting
  boolean find(String searchField) {
    Pattern p = Pattern.compile(searchField);
    for (PartitionFieldNode node : roots) {
      if (find(node, p)) {
        return true;
      }
    }
    return false;
  }
Given a Java regex string pattern, checks if the the partitionFieldNode tree
has any node whose fieldName matches the given pattern
@param searchField
@return
standalone-metastore/metastore-server/src/main/java/org/apache/hadoop/hive/metastore/PartitionProjectionEvaluator.java