can somoene explain this code in the Role and Permission, the getter in both files I dont know what is the purpose and also the enum in Permission file each attribute has an argument why theirs an argument if theirs already a ROLE ?

Permission.java

`package com.crackit.SpringSecurityJWT.user;

import lombok.Getter;
import lombok.RequiredArgsConstructor;

@RequiredArgsConstructor
public enum Permission {

ADMIN_READ("admin:read"),
ADMIN_CREATE("admin:create"),
MEMBER_READ("management:read"),
MEMBER_CREATE("management:create"),

;

@Getter
private final String permission;

}

`

Role.java

package com.crackit.SpringSecurityJWT.user;

import lombok.Getter;
import lombok.RequiredArgsConstructor;
import org.springframework.security.core.authority.SimpleGrantedAuthority;

import java.util.Collections;
import java.util.List;
import java.util.Set;
import java.util.stream.Collectors;


import static com.crackit.SpringSecurityJWT.user.Permission.*;

@RequiredArgsConstructor
public enum Role {
  ADMIN(
          Set.of(
                  ADMIN_READ,
                  ADMIN_CREATE,
                  MEMBER_READ,
                  MEMBER_CREATE
          )
  ),
  MEMBER(
          Set.of(
                  MEMBER_READ,
                  MEMBER_CREATE
          )
  )

  ;

  @Getter
  private final Set<Permission> permissions;

  public List<SimpleGrantedAuthority> getAuthorities() {
    var authorities = getPermissions()
            .stream()
            .map(authority -> new SimpleGrantedAuthority(authority.getPermission()))
            .collect(Collectors.toList());
    authorities.add(new SimpleGrantedAuthority("ROLE_" + this.name()));
    return authorities;
  }
}

User.java

package com.crackit.SpringSecurityJWT.user;

import jakarta.persistence.*;
import lombok.AllArgsConstructor;
import lombok.Builder;
import lombok.Data;
import lombok.NoArgsConstructor;
import org.springframework.security.core.GrantedAuthority;
import org.springframework.security.core.authority.SimpleGrantedAuthority;
import org.springframework.security.core.userdetails.UserDetails;

import java.util.Collection;
import java.util.List;

@Entity
@Table(name = "_user")
@Data
@Builder
@AllArgsConstructor
@NoArgsConstructor
public class User implements UserDetails {

    @Id
    @GeneratedValue
    private Integer id;

    private String firstName;

    private String lastName;

    private String email;

    private String password;

    @Enumerated(EnumType.STRING)
    private Role role;


    @Override
    public Collection<? extends GrantedAuthority> getAuthorities() {
        return role.getAuthorities();
    }

    @Override
    public String getUsername() {
        return email;
    }

    @Override
    public boolean isAccountNonExpired() {
        return true;
    }

    @Override
    public boolean isAccountNonLocked() {
        return true;
    }

    @Override
    public boolean isCredentialsNonExpired() {
        return true;
    }

    @Override
    public boolean isEnabled() {
        return true;
    }
}