How to specify the priority of a source?

[UtkarshVerma]

I am using opts_extend for my blink.cmp config. When I add support for LuaSnip in another file like so:

  -- other blink.cmp config stored in a separate file.
  {
    "blink.cmp",
    dependencies = { "LuaSnip" },
    ---@type plugins.blink.config
    opts = {
      snippets = {
        expand = function(snippet)
          require("luasnip").lsp_expand(snippet)
        end,
        active = function(filter)
          if filter and filter.direction then
            return require("luasnip").jumpable(filter.direction)
          end

          return require("luasnip").in_snippet()
        end,
        jump = function(direction)
          require("luasnip").jump(direction)
        end,
      },
      sources = {
        default = { "luasnip" },
      },
    },
  },

This works but since sources.default is appended to the list, luasnip gets the least priority. Is there a way I can specify the priority of the luasnip source here without having to copy the entire list?

In a gist, I want something like group_index from nvim-cmp.