You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: disk_usage_eviction_task.rs
    path of file: ./repos/neon/pageserver/src
    
    the code of the file until where you have to start completion: //! This module implements the pageserver-global disk-usage-based layer eviction task.
//!
//! # Mechanics
//!
//! Function `launch_disk_usage_global_eviction_task` starts a p
    
    fn max_usage_pct_pressure() {
        use super::EvictionOrder;
        use super::Usage as _;
        use std::time::Duration;
        use utils::serde_percent::Percent;

        let mut usage = Usage {
            config: &DiskUsageEvictionTaskConfig {
                max_usage_pct: Percent::new(85).unwrap(),
                min_avail_bytes: 0,
                period: Duration::MAX,
                #[cfg(feature = "testing")]
                mock_statvfs: None,
                eviction_order: EvictionOrder::default(),
            },
            total_bytes: 100_000,
            avail_bytes: 0,
        };

        assert!(usage.has_pressure(), "expected pressure at 100%");

        usage.add_available_bytes(14_000);
        assert!(usage.has_pressure(), "expected pressure at 86%");

        usage.add_available_bytes(999);
        assert!(usage.has_pressure(), "expected pressure at 85.001%");

        usage.add_available_bytes(1);
        assert!(usage.has_pressure(), "expected pressure at precisely 85%");

        usage.add_available_bytes(1);
        assert!(!usage.has_pressure(), "no pressure at 84.999%");

        usage.add_available_bytes(999);
        assert!(!usage.has_pressure(), "no pressure at 84%");

        usage.add_available_bytes(16_000);
        assert!(!usage.has_pressure());
    }