local function solve()
  local n, m = io.read("*n", "*n")
  local c = {}
  for i = 1, n do
    c[i] = 0
  end
  for i = 1, m do
    local a, b = io.read("*n", "*n")
    c[a] = c[a] + 1
    c[b] = c[b] + 1
  end
  local box = {}
  for i = 1, n do
    local v = c[i]
    if box[v] then return true end
    box[v] = true
  end
  return false
end

local q = io.read("*n")
for iq = 1, q do
  print(solve() and "Yes" or "No")
end