code: private StmtCommonTableScan resolveCommonTableByName(String tableName, String tableAlias) {
          StmtCommonTableScan answer = null;
          StmtCommonTableScanShared scan = null;
          for (AbstractParsedStmt scope = this; scope != null && scan == null; scope = scope.getParentStmt()) {
              scan = scope.getCommonTableByName(tableName);
          }
          if (scan != null) {
              answer = new StmtCommonTableScan(tableName, tableAlias, scan);
          }
          return answer;
      }
docs: Look for a common table by name, possibly in parent scopes.
  This is different from resolveStmtTableByAlias in that it
  looks for common tables and only by name, not by alias.  Of
  course, a name and an alias are both strings, so this is kind
  of a stylized distinction.
  
  @param tableName
  @return