src/java.base/share/classes/java/time/chrono/ChronoPeriodImpl.java

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  import java.time.temporal.TemporalAmount;
  import java.time.temporal.TemporalQueries;
  import java.time.temporal.TemporalUnit;
  import java.time.temporal.UnsupportedTemporalTypeException;
  import java.time.temporal.ValueRange;
- import java.util.Arrays;
- import java.util.Collections;
  import java.util.List;
  import java.util.Objects;
  
  /**
   * A period expressed in terms of a standard year-month-day calendar system.
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*** 103,114 ****
      private static final long serialVersionUID = 57387258289L;
  
      /**
       * The set of supported units.
       */
!     private static final List<TemporalUnit> SUPPORTED_UNITS =
!             Collections.unmodifiableList(Arrays.<TemporalUnit>asList(YEARS, MONTHS, DAYS));
  
      /**
       * The chronology.
       */
      private final Chronology chrono;
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      private static final long serialVersionUID = 57387258289L;
  
      /**
       * The set of supported units.
       */
!     private static final List<TemporalUnit> SUPPORTED_UNITS = List.of(YEARS, MONTHS, DAYS);
  
      /**
       * The chronology.
       */
      private final Chronology chrono;