Error in `load_all()`: could not find function "load_all"

#     Tests for the rp.plot4d and rp.spacetime functions
x <- cbind(long = 2 * z /n + rnorm(n), lat = 2 * z /n + rnorm(n))
expect_no_error(pnl <- rp.plot4d(x, z, y))
expect_no_error(pnl <- rp.plot4d(x, z, y, coords = c(0, 0)))
expect_no_error(pnl <- rp.plot4d(x, z, y, retain.location.plot = TRUE))
expect_no_error(pnl <- rp.plot4d(x, z, y, location.plot = FALSE))
expect_no_error(pnl <- rp.plot4d(cbind(x[,1], x[,2]/2), z, y, eqscplot = TRUE))
expect_no_error(pnl <- rp.spacetime(x, z, y))
position <- with(quakes, cbind(long, lat))
expect_no_error(pnl <- rp.plot4d(position, quakes$depth, quakes$mag))
# This inexplicably fails on some platforms.
# Error in xord[, 1] : incorrect number of dimensions
x       <- cbind(long = 2 * z /n + rnorm(n), lat = 2 * z /n + rnorm(n))
model   <- list(x = model.x, y = model.y, z = model.z)
#    expect_no_error(pnl <- rp.plot4d(x, y, z))
#    expect_no_error(pnl <- rp.plot4d(x, z, y, model))
#    expect_no_error(rp.plot4d(x, z, y, model, panel = FALSE, z.window.pars = c(z0 = 800, zsd = 30)))
rp.plot4d(x, z, y, model, panel = FALSE, z.window.pars = c(z0 = 800, zsd = 30))
# location <- cbind(longitude, latitude)
# mapxy       <- maps::map('world', plot = FALSE,
#             foreground.plot = function() map(mapxy, add = TRUE))
# model <- mgcv::gam(logSO2 ~ s(location1, location2, year))
# loc1  <- seq(min(location1), max(location1), length = 30)
# loc2  <- seq(min(location2), max(location2), length = 30)
# yr    <- seq(min(year), max(year), length = 30)
# newdata <- expand.grid(loc1, loc2, yr)
# names(newdata) <- c("location1", "location2", "year")
# model <- list(x = cbind(loc1, loc2), z = yr,
#               y = array(model, dim = rep(30, 3)))
# rp.plot4d(location, year, logSO2, model,
# rp.plot4d(location, year, logSO2, mdl,
# rp.plot4d(cbind(Doy, DO), Station, location.plot = FALSE)
# rp.plot4d(cbind(Station, DO), Doy, location.plot = FALSE)
# group   <- factor(c("before 1985", "after 1985")[1 +
# rp.plot4d(cbind(doy, do), station, group,
#      col.palette = c("red", "green"), location.plot = FALSE)
# points( 0.3,    0, col = hsv(rgb2hsv(0, 0, 1) * alpha), pch = 16, cex = 30)
# x <- cbind(2 * z /n + rnorm(n), 2 * z /n + rnorm(n))
# for (i in order(alpha)) points(x[i,1], x[i,2], pch=16, col = clr[i])
# # See also the material in test-rp-plot4d-clyde.r