old_contents: from django.db import models
  from django.contrib import admin
  
  
  class Cluster(models.Model):
  
      name = models.CharField(max_length=64, primary_key=True, blank=False)
      description = models.CharField(max_length=1024, null=True, blank=True)
  
      def __str__(self):
          return self.name
  
      class Admin:
          pass
  
  
  class Server(models.Model):
  
      cluster = models.ForeignKey('Cluster')
      address = models.CharField(max_length=80, primary_key=True, blank=False)
      rest_username = models.CharField(max_length=32, blank=False)
      rest_password = models.CharField(max_length=64, blank=False)
      ssh_username = models.CharField(max_length=32, blank=False)
      ssh_password = models.CharField(max_length=64, blank=True)
      ssh_key = models.CharField(max_length=4096, blank=True)
      description = models.CharField(max_length=1024, blank=True)
  
      def __str__(self):
          return self.address
  
      class Admin:
          pass
  
  
  class BucketType(models.Model):
  
      type = models.CharField(max_length=9, primary_key=True)
  
      def __str__(self):
          return self.type
  
      class Admin:
          pass
  
  
  class Bucket(models.Model):
  
      class Meta:
  
          unique_together = ["name", "cluster"]
  
      name = models.CharField(max_length=32, default="default")
      cluster = models.ForeignKey("Cluster")
      type = models.ForeignKey("BucketType")
      port = models.IntegerField(default=11211, blank=True)
      password = models.CharField(max_length=64, blank=True)
  
      def __str__(self):
          return self.name
  
      class Admin:
          pass
  
  
  class Metric(models.Model):
  
      class Meta:
  
          unique_together = ["name", "cluster", "server", "bucket"]
  
      cluster = models.ForeignKey("Cluster")
      server = models.ForeignKey("Server", null=True, blank=True)
      bucket = models.ForeignKey("Bucket", null=True, blank=True)
      name = models.CharField(max_length=64)
  
      def __str__(self):
          return self.name
  
      class Admin:
          pass
  
  
  class Event(models.Model):
  
      class Meta:
  
          unique_together = ["name", "cluster", "server", "bucket"]
  
      cluster = models.ForeignKey("Cluster")
      server = models.ForeignKey("Server", null=True, blank=True)
      bucket = models.ForeignKey("Bucket", null=True, blank=True)
      name = models.CharField(max_length=64)
  
      def __str__(self):
          return self.name
  
      class Admin:
          pass
  
  admin.site.register(Cluster)
  admin.site.register(Server)
  admin.site.register(Bucket)
  admin.site.register(Metric)
  admin.site.register(Event)
  
new_contents: from django.db import models
  from django.contrib import admin
  
  
  class Cluster(models.Model):
  
      name = models.CharField(max_length=64, primary_key=True, blank=False)
      description = models.CharField(max_length=1024, null=True, blank=True)
  
      def __str__(self):
          return self.name
  
      class Admin:
          pass
  
  
  class Server(models.Model):
  
      cluster = models.ForeignKey('Cluster')
      address = models.CharField(max_length=80, primary_key=True, blank=False)
      rest_username = models.CharField(max_length=32, blank=False)
      rest_password = models.CharField(max_length=64, blank=False)
      ssh_username = models.CharField(max_length=32, blank=False)
      ssh_password = models.CharField(max_length=64, blank=True)
      ssh_key = models.CharField(max_length=4096, blank=True)
      description = models.CharField(max_length=1024, blank=True)
  
      def __str__(self):
          return self.address
  
      class Admin:
          pass
  
  
  class BucketType(models.Model):
  
      type = models.CharField(max_length=9, primary_key=True)
  
      def __str__(self):
          return self.type
  
      class Admin:
          pass
  
  
  class Bucket(models.Model):
  
      class Meta:
          unique_together = ["name", "cluster"]
  
      name = models.CharField(max_length=32, default="default")
      cluster = models.ForeignKey("Cluster")
      type = models.ForeignKey("BucketType")
      port = models.IntegerField(default=11211, blank=True)
      password = models.CharField(max_length=64, blank=True)
  
      def __str__(self):
          return self.name
  
      class Admin:
          pass
  
  
  class Metric(models.Model):
  
      class Meta:
          unique_together = ["name", "cluster", "server", "bucket"]
  
      cluster = models.ForeignKey("Cluster")
      server = models.ForeignKey("Server", null=True, blank=True)
      bucket = models.ForeignKey("Bucket", null=True, blank=True)
      name = models.CharField(max_length=64)
  
      def __str__(self):
          return self.name
  
      class Admin:
          pass
  
  
  class Event(models.Model):
  
      class Meta:
          unique_together = ["name", "cluster", "server", "bucket"]
  
      cluster = models.ForeignKey("Cluster")
      server = models.ForeignKey("Server", null=True, blank=True)
      bucket = models.ForeignKey("Bucket", null=True, blank=True)
      name = models.CharField(max_length=64)
  
      def __str__(self):
          return self.name
  
      class Admin:
          pass
  
  admin.site.register(Cluster)
  admin.site.register(Server)
  admin.site.register(Bucket)
  admin.site.register(Metric)
  admin.site.register(Event)
  
subject: remove redundant line breaks