docs: public SingleFieldConstraint getLHSBoundField(final String var) {
          if (this.lhs == null) {
              return null;
          }
          for (int i = 0; i < this.lhs.length; i++) {
              IPattern pat = this.lhs[i];
  
              SingleFieldConstraint fieldConstraint = getLHSBoundField(pat,
                                                                       var);
              if (fieldConstraint != null) {
                  return fieldConstraint;
              }
          }
  
          return null;
      }