...

   <T extends Metric> T metric(T metric);

    /** Registers LongGaugeRemoves custom metric named '"custom." + {@code name}'. */
   void longMetricremoveMetric(String name, LongSupplier valueSupplier, @Nullable String description);
 );

   /** @return custom Metric registry named '"custom." + {@code name}'. */
   ReadOnlyMetricRegistry registry(String name);

   
   // Simple type metrics.

   /** Registers LongMetric. */
   LongConsumer longMetric(String name, @Nullable String description);

   /** Registers DoubleGaugeDoubleMetric. */
   voidDoubleConsumer doubleMetric(String name, DoubleSupplier valueSupplier, @Nullable String description);

   /** Registers DoubleMetricBooleanMetric. */
   DoubleConsumerConsumer<Boolean> doubleMetricbooleanMetric(String name, @Nullable String description);

   /** Registers BooleanGaugeObjectMetric. */
    void booleanMetric<T> Consumer<T> objectMetric(String name, BooleanSupplierClass<T> valueSuppliervalueType, @Nullable String description);


   // Might be useful the gauges:

   /** Registers BooleanMetricDoubleGauge. */
   Consumer<Boolean>void booleanMetricdoubleMetric(String name, DoubleSupplier valueSupplier, @Nullable String description);

   /** Registers ObjectGaugeBooleanGauge. */
   <T> void objectMetricbooleanMetric(String name, Class<T> valueType, Supplier<T>BooleanSupplier valueSupplier, @Nullable String description);

   /** Registers ObjectMetricObjectGauge. */
   <T> Consumer<T>void objectMetric(String name, Class<T> valueType, Supplier<T> valueSupplier, @Nullable String description);

   /** Removes custom metric named '"custom." + {@code name}'. Registers LongGauge. */
   void removeMetriclongMetric(String name);
,   /** @return custom Metric registry named '"custom." + {@code name}'. */
   ReadOnlyMetricRegistry registry(String nameLongSupplier valueSupplier, @Nullable String description);
}

Risks and Assumptions

    Custom metrics can affect the performance.

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